You can get a rebuilt unit from rockauto.com for about $83.00, and "Knocker-Loose" or WD-40 should help remove the rusted screws.
As a last resort, just drill the old screws out, clean up the threads, and install new screws.
[QUOTE=Patrick T.]I have just had my truck diagnosed with a bad HCU. Is there anyone out there that has found a reliable replacement unit, possibly from another remanufacturer other than Ford. I know that you can get a remaned Control Module. I just don't want to pay the dealer $600 for something that I can change myself. Also, the technician at the dealership stated that if they could not remove the Control Module because the screws are rusty they would have to replace that too. So my second questions is there a solvent that can clean up the Control Module screws so I can remove them?