Is it possible to change the screen of a 42S?

[John R]

It's doable, but it's not easy, and the case will never be quite as sturdy again because you need to cut through things that were never meant to be cut through. Here is a good primer to HP-42S (or other Pioneer) disassembly:

http://www.hpmuseum.org/guest/brogpion.htm

Good luck, and let us know how it goes!