Edit: Looks like I'm not going to wrap up the job this weekend. Stuck staying here for through Monday at least. Damn retrofit killed a day, and then working my way through some build quality problems. Customer won't work Saturday since they already work tens the rest of the week. Can't say I blame them.
Themken: Rotten luck but it is advised against shipping computers with a big heatsink attached to the processor. In parts is much safer but then we have the problem of you not knowing how to put it together.
tinyE: My brother wants to order a new one and talk me through installing it, but that doesn't look like something I am even remotely capable of.
People keep saying this, and it's pretty much true: if you can work a screwdriver then you can do this repair. Just gotta make sure the people on both ends of the conversation - the fixer and the talker-througher - are patient.
Or make a road trip down to southern WI and I'll do it for you. : )