If I have an apk can I remove the current signing and some how re-sign it with a different .keystore file and still have the application install?
Update: I managed to get it to work with Jorgesys' solution and where I messed up before was that I unzipped the .apk then rezipped it after removing the META-INF folder and changed the file extension back into .apk. What I should have done is simply opened it with winzip and delete the folder inside of winzip.
1) Change the extension of your .apk to .zip
2) Open and remove the folder META-INF
3) Change the extension to .apk
4) Use the jarsigner and zipalign with your new keystore.
hope it helps