A lot of riders would take the wrist pins out of the pistons so the pistons will stay in the cylinders and the heads stay on top of the cylinders. It's OK to do that way but be very careful when reinstalling the wrist pin circlips. The circlips have to be prooved or proofed. There's not a lot you can see when performing this operation and everything is still attached to the engine. There is just not a lot of room to stick your head in there.
Even a circlip installed in a place where you can see what is happening is proofed. Once installed, you think it's in place, the circlip is spun in it's bore. Spin it enough so that you can see it is seated. That's it. Prove all circlips.
My friend lost a piston, cylinder, cam shaft, oil pump and lifters. Because a circlip was not fully seated.