As I was pulling apart an eMachines E732 for a friend, I realised I should make a video for anybody else unfortunate enough to be doing the same thing. These machines are reasonably straightforward to disassemble, with accessible RAM, hard drive and wireless card.
I originally said the CPU might be replaceable “if it is socketed” because I had not checked. :P The service guide answers that one: the documented E732-family models use an rPGA processor package, and the official procedure includes removing and replacing the CPU. That establishes a socketed processor, rather than compatibility with any replacement CPU.
The guide also distinguishes the E732/E732Z models with Intel HD Graphics from the E732G/E732ZG variants with discrete ATI graphics. My original observation was that the base model felt roomy without the extra graphics hardware; I had not identified the graphics chip in the video.