If you have not jailbroke your iPhone, you will need to do that first. You can check out our Jailbreak page for tutorials on jailbreaking your iPhone or iPod Touch.
Deleting a source from Installer will remove all of the applications from Installer that are available through that source. It will not delete applications that you already have installed that are from that source. However, after you delete the source, you will no longer see updates for the applications you have installed from that source.
8. Wait for the source to delete. This will take a few seconds.