Pry from the cocking lever opening, then the trigger guard, doing a little each time and swapping back and forth.
The side plate holds the internals in place but they're not under sideways tension so nothing will fly out at you. Having said that, the hammer/spring linkage is literally just resting in place and gets jarred loose very easily. It also has a donut-shaped bushing where it interfaces with the hammer that's not pressed on or anything so it might come out with the linkage and then fall off. Remove that part carefully and set it aside.
Don't force the side plate on. If it's not dropping in, something is out of alignment and needs to be fixed.