Actually, the way i have always understood it, you need to retain the signature of the rom. Which isn't possible without having the keys that were used when it was signed, or resigning the whole rom.
What you would need to do is decompile the apk, make your changes recompile the apk and then copy the files you edited to the still zipped original apk.
Here's a guide that may offer some assistance.
http://androidforums.com/esteem-all...roperly-decompile-recompile-apks-apktool.html
And as far as uploading one of my own... I don't have anything that will work with the newer versions of ctmod, but I should have something lying around in my prevail directory... I'll have a look tonight or tomorrow and see what up can come up with