Two things I wanted to add. When I removed the final drive I was left with the drive shaft still connected to the transmission. Mr Harris in his video does not say that you need to pry it from the spring clip to remove it.
The driveshaft doesn't need to be
pried from its clip. If the swingarm is removed, grasp the driveshaft firmly, jerk it rearward and it will be released. If the swing arm is still installed, a vicegrip clamped on the protruding portion of the driveshaft and then smacked rearward with a mallet will also release it.
Second on the list is how I made my guides which are necessary to keep from bending the clutch rod.
The bolts needed to secure the transmission are 8mm 1.25. I purchased two 4" 5/16's bolts then cut off the heads. You can partially thread these bolts in the transmission mounting holes but be careful as they are standard threads. Just enough so they will stay put when you remove the transmission.
I don't recommend this procedure because it relies too much on luck. If guide pins are made for removal of the transmission, their threads should be of the same diameter and pitch as the threads in the engine so they can be threaded
securely—not "partially"—into it. Coupling these parts with threads that don't match could lead to cross-threading and then to extra time and cost to repair damaged threads in the engine. Correctly-sized bolts are not costly. If they're not available locally, send away for them.
Clamping threaded portions of a bolt in the hard jaws of a vice could damaged them then they could damage whatever threads are receiving them.