Need to edit a .cfg file within an ISO, what software can I use

My laptop came with home premium, when I remove all the crapware it breaks my wifi(must reinstall driver every boot), the recommendation from asus was to reinstall, of course they gave me a 32 bit recovery disk which doesn't work when the laptop wants x64:naughty:
Ironically I'm actually trying NOT to just install a pirate copy of windows 7 ultimate(dumb ain't I?) and I've wasted about 2 hours on this, I've got a virgin copy of windows 7.iso, alll I want is to edit the ei.cfg from RETAIL to OEM, a 5 second fix in notepad, I'll be damned if I can find a program that will let me either take it apart, edit, save and have it turn back into a bootable ISO, or even better to just edit the damn file within the ISO.
What software could I use, and how would I do it?:frusty::frusty::frusty::frusty::frusty:
I just want the damn thing to work, without 5 hours of de crap work yet again, only to have it break the same way.