Apps Modifying .apk's - signing

[Legend07]

I'm trying to modify some apps, Handcent for example, by opening it with 7zip, and editing the .png's. Then I'd need to resign them, which I've tried doing with some autosign tools, but when I move it to my phone and try to install it, it tells me that the app could not be installed. I assume this is because I have not resigned it correctly.

Could anyone please tell me ALL I would need to just resign .apk's so they can be installed on my phone.

I have looked at a lot of how-to's about this, but I can't seem to do it right.
Thanks.

 

[rainfreak]

This will do the trick nicely.

Android APK & Zip Signer

 

[Legend07]

Thanks man!

 

[cp1]

You probably need to uninstall handcent to install your new version, since you can't resign it with the same key that the original had.