The trigger should not be too difficult to fix if you have the right materials. My friend lost part of the trigger piece on his 4100's after it broke so I had to improvise; I used a thin plastic sheet and cut out a new piece.
In either case, regardless of whether you're reinforcing or fixing, you'll need a sheet of metal and cutters for them. See the
snapped trigger repair at SSC for more details. You will have to apply two strips to the side of the trigger piece; applying just one to the bottom may not work well. The process of reinforcement is pretty much the same as fixing it.