How to reset passcode on iPhone without restoring?

I recently downloaded a new Cydia lockscreen but unknowingly didn't change my passcode back over to a numbered one and I think it is glitching. I'm unable to get into my iphone at all. Is there a way I can change the passcode without restoring?

Put iPhone into safe mode and remove the tweak that is causing trouble.

Steps here: http://www.jailbreakmodo.com/how-to-enter-into-iphone-in-safe-mode-to-fix-crashed-apps.html

Hope this helps!

Put your iPhone into recovery mode with this free and simple tool - Tenorshare ReiBoot. It also allows you to exit iPhone recovery mode with one click. You don't need to restore your iPhone and lose data. Just have a try if needed. Get the totally free download from:

http://www.any-data-recovery.com/product/free-iphone-ipad-ipod-reboot.html

I'm an iOS Technical Advisor for Apple.

If you do what the previous answers have said, you are going to void the warranty on the phone. Also, there's a very good chance that it will brink your phone, meaning the phone will never work again.