I've never worked on an 1100 so I may be a bit off, but...
Did you remove the O-ring an clean it? If it is still in good shape, still pliable, it should be okay to reuse (I usually replace them but many do not).
Are any of the threads stripped?
All the screws should be the same length so it should not matter where they go (unless an 1100 is different).
You'll want to catch the oil in a clean container so you can put it back in. Drain it through the drain plug, it'll be easier. Remove the filter cover and clean everything (the mating surface on the engine, the O-ring, the groove the O-ring sits in). I usually coat the O-ring in clean motor oil before (re)installing in the groove.
When tightening, keep in mind that the steel screws are going into aluminum and it is possible to strip them. Use the allen wrench that came in the tool-kit. They are short for a reason, it helps to keep from over-tightening fasteners.
Hope this helps,
Tom