If you installed them through Cydia or Rock, you can uninstall them through the same process you used to install them. If you manually installed them via SSH, you will have to SSH back into your phone and manually remove them. Hope that helps.
If the "little lock icon" has the same file name as the original slider, and if you didn't back the file(s) before overwriting them, then you are out of luck. You will have to restore and re-jailbreak. Always always always backup files before you overwrite them.
Also, if you do plan on restoring and re-jailbreaking, do not upgrade to the latest iTunes. Spirit and the latest build of iTunes aren't compatible at the moment.