This thread includes some pointers based on my experiences refurbishing/repainting or covering Gen 3 System Cases in Line-X. There are many ways to skin this cat but this is my approach.
Prepping the cases:1 - Remove the straps: Each case has a strap that keeps it from opening more than ninety degrees when it's mounted on the bike. One end has a simple metal snap. The other end pivots on a small black plastic retaining pin. Rotate the pin so that you can see the slot in the middle of it, pinch the ends nearest the case shell with some needle-nose pliers and pry it out from the other end with a knife or small screwdriver. Set the straps and pins aside where you won't misplace them.
2 - Separate the case halves: The case halves are held together by plastic hinges on rails at the bottom. Each hinge slides out from the middle. What I've found works well for removing the hinges is to pound the hinges off with a one inch chisel and a hammer.
If your hinges are getting old then the replacement part number is 46452300039. There's a total of four - two for each case.
(At this point you can set the inner halves aside since the outside halves are the only painted part.)
3 - Remove the locks: The locks are held onto the outer case halves by simple rivets that can be drilled out from the inside of the case. When drilling the backs of the rivets off the friction generated by the drilling can generate a fair amount of heat which, if you're not careful, will melt the surrounding plastic so use a good sharp drill bit and do it as quickly as possible.
4 - Remove the roundels and reflectors: (Some cases have "Touring" emblems instead of reflectors.) These are held on by double-sided tape and can be carefully and slowly pried off. If you want to replace them with new ones then here are the part numbers:
Roundels: 46542300045
Red reflectors: 46542300047
Yellow reflectors: 46542300134
"Touring" emblems: 46542300046
5 - Remove the rubber scuff pads: This is the tricky part as the two rubber scuff pads on each case outer are attached around their perimeters with some pretty stout double-sided tape with glops of some sort of adhesive in the center. The scuff pad rubber is EXTREMELY easy to tear (and expensive to replace, of course) so take your time and be careful when removing the scuff pads.
On each scuff pad, carefully peel back one of the corners to get started on the double-sided tape. I use a good sharp 1/4-1/3" chisel and slowly work my way down the length of the scuff pad, first separating the double-sided tape on the perimeter and then the glops of adhesive in the center.
Once you have the scuff pads off, remove any residual double-sided tape from the backs of the pads and the case halves, being careful not to tear the rubber. Also, get rid of as much of the residual adhesive as you can as well.
6 - Tape off the portions you don't want covered: Using painter's tape, (I just use the blue stuff from the hardware store) tape off the places that you don't want repainted:
a - The bottoms of the wells for the roundels and reflectors
b - The bottoms of the wells for the scuff pads
c - The rail where the hinges mount
7 - Repaint them or have them covered in a truck bed liner such as Line-X: You have several options here:
a - Get them professionally repainted and clear-coated: If you're going for color-matched System Cases then I'd recommend finding a painter that uses the PPG paint matching computer and take him one of your battery covers to do the paint matching.
b - Paint them yourself: I'm not an expert on paint prep or painting so you should do your own research on that front but if you're painting System Cases that are just plain unpainted ABS plastic then be sure to use a primer that's made for painting plastics or use a paint like Krylon Fusion that's specifically made to adhere to plastics.
Krylon Fusion in a matte finish black is available at your local Sherwin-Williams paint store. They probably won't have it in stock but you can call your local shop and have them order you a can or two of it.
c - Coat them in truck bed liner like Line-X Some people report having good luck with rattle-can truck bed liner like the stuff from Duplicolor but I prefer to have mine professionally done by a local Line-X shop. They use a dual headed spray gun that mixes the two parts of the liner material (similar to an epoxy) as it's sprayed and is extremely durable.
If you have several truck bed liner shops in your area then get quotes from all that are within a reasonable distance as they are usually independently owned franchises so some may be less expensive than others.
Putting things back together...8 - If you used truck bed liner: When applied, truck bed liners like Line-X usually add about 1/16" or so of thickness to whatever it's applied to. Once you've cut off the tape from the taped off areas with an Exacto knife or whatever, you'll find that the walls of the wells for the emblems and scuff pads, as well as the mounting holes for the locks, are thicker than they used to be be. Therefore, the scuff pads, emblems and locks won't fit right back on. What I do is trim the sides of the wells back down with a Dremel grinding wheel.
Also, on the Gen 3 System cases, the lip of the outer case that mates with the rubber seal in the inner case half will be larger then it once was. Again, using a Dremel grinding wheel, go around the edge of the outer case half and bevel it so that the case halves will fit snugly together again.
9 - Re-attach the scuff pads: What I've found works well and is waterproof and durable is to get a caulking gun tube of roof repair sealant at the hardware store and use a caulking gun to put the scuff pads back on. Once you've done that, wrap some belts or nylon straps around the outer case half to keep the scuff pads in place and let them sit for 24 hours or so in order to give the roofing sealant some time to set/cure. (Read the instructions on the tube to find out what the curing time is.)
10 - Re-attach the roundels and reflectors: Using either your caulking tube of roofing sealant or some good weatherproof double-sided tape, re-attach the roundels and reflectors.
11 - Rivet the locks back on: Using a pop rivet tool like the one pictured below and available at most hardware stores, rivet the locks back onto the case outers. (I don't know the size of the rivets off the top of my head.) I prefer to use steel rivets since they're stronger then aluminum ones.
12 - Put the hinges back on: With the holes in the hinges facing the center, put the case halves together and, using a short piece of 1x2 wood and a hammer, tap the hinges back into place.
13 - Replace the straps.14 - Mount the System Cases on your bike: And go for a ride....
