I am fixing a gameboy advance but the start/select and the up buttons are not working. Also i have to wiggle the batteries around for it to even turn on, and then it turns on and off by it self. Help!

So some of the nickel on the up button and start/select is missing. I’ve seen people fix this stuff with small wires but i dont know how. Should i resodder the battery holders to fix the battery problem? I have pictures but i can’t upload them. I will try to.

Posted the pictures on reddit.

This is my profile u/asge1868

hope you can see the pictures. Any Help is appreciated