Replace spring in yale P77 lock - Yale Locks P77 Traditional Nightlatch Enb/Pb Cylinder 60 Mm Backset Visi Pack

http://www.yale.com/uploadedFiles/Yale/Content/NorthAmerica/Product_Information/Product_Brochures/Class5_GP060-070VX-Veracitor-Specification-Sheet(3).pdf
http://store.intellaliftparts.com/blog/decode-yale-forklift-model-number
https://www.scribd.com/doc/244438912/manual-yale-pdf

https://www.lsc.com.au/content/Documents/products/Yale%20Fire%20Safe%20Manual.pdf

Yale battery operated safes have a manual override function for which keys are supplied.

Sorry, I don't know anything about them.

this step by step guide should help you reset the lock, if its not the exact same lock, its the closest thing that Yale currently makes. Be aware you cannot reset locks like these unless they are open already, atleast not to my knowledge

Combination Cable lock Reset the combination of Yale travel lock Secure...

You can't. Make sure the cylinder is in the upright position, and tap the lock on a bench face down (very hard) it may dislodge it enough to grab it with some tweezers.If no luck, throw it away.

All I ever do is start at 001and work my way to 999

I researched the model number with no success. I assume that you live in the United States as this is a Britain-based company. So I'm providing you with a link to their US support information:

http://www.yaleresidential.com/en/yale/yale-USA/Contact-us/

and I encourage you to call them directly with your request.

Good luck!