Aaron, it pretty much is easy. A couple of things I do.
I have small squares of 20mm thick acrylic I use as pads for working on, about two inches square. I take a wad of blue tac and stick the part to it on the block. This way I don't have to handle the part.
I use the curved blade scalpel for cutting the PE part loose from the frame, cutting the tab loose as close to the part as you can. The idea of putting some tape on the back then cutting so the part doesn't disappear, was posted here a couple of days ago and is a good ides. I use a ball of blue tac, rolled to a point at one end for picking up the part. Then use a piece of wire to apply some Super Glue to the place you want to put the part. hold the part over the glue dot, and with a pointed exacto press the piece in place, pulling it off the blue tac and hold it there for a second or two till the SG sets.
When I apply the face of the instrument panel I use the white glue. I dot glue to the instrument faces, all of them, with a tooth pick end I have dipped into the glue. Then place the face, using the pointed blue tac again, over the instruments, press in place with the blade again, squishing the glue thru the holes for the instruments. Let it dry and the glue goes clear at the instruments.
Just make sure the plastic is FLAT where you're going to place the PE. Use the pointed blue tac to handle the PE, the stuff pops out of tweezers. If you want plastic blocks to work on, hit the plastic suppliers and see if you can find some off cuts.
Hope I haven't been too wordy.