Rated 5 out of 5 stars

@toxiclabs: Thanks for that link. Once renamed, it works perfectly!

I have absolutely NO IDEA why I was having such a problem doing this, since I've modded other versions of the add-on. But thanks again to all who attempted to assist this simpleton.

Rated 1 out of 5 stars

1) I edited gmServiceGmail.js and made the appropriate changes.
2) I saved gmServiceGmail.js in a miscellaneous directory
3) I can't save gmServiceGmail.js to {582195F5-92E7-40a0-A127-DB71295901D7}.xpi
4) No matter what manipulations to {582195F5-92E7-40a0-A127-DB71295901D7}.xpi I do with winrar, whether I change the extention to .zip, or leave it as .xpi or change it to .rar

Nothing I save will be accepted. I can't save it to {582195F5-92E7-40a0-A127-DB71295901D7}.xpi, packed, unpacked or any format.

Rated 1 out of 5 stars

5. Save the file, overwrite the existing gmServiceGmail.js with this one and VIOLA! After restarting Firefox you should be all set.

Nice, but how in god's name do I save the modified file and have it recognized? Where do I save the modified file to? Do I have to re-import it into winrar? How do I do that, exactly, in that obscure program when there's no method to import the modified file?