sudomod

I was just modifying my screen to use five volts, however I can no longer get wires onto it because the metal where I removed the chip has come off and there's nothing to connect to

Use a magnifier to look which trace the solder pad you lifted is connected to. Once found, you can scratch the board coating and solder directly to it. This is a similar approach on how @wermy soldered the button pads to the controller board.

Picture of the board? There may be another set of 4 contacts you could connect the wire to

Did you ever get your screen to work. I just made the same mistake...

Sorry I haven't worked on my gbz in a while but I'm starting up again still confused what to do about this, here's a picture of it

As chiz said, either tap into the traces or,if everything else fails, you can try to carefully drill a hole into the beginning of the trace, where the pad was and fill this with solder. This worked for my USB DAC where i managed to screw up the pads.
Put a piece of electronical tape on the bottom, so the solder will not drop out when you heat it to solder on a wire or something.

Edit:
What chiz meant was, try to find the traces that lead to the pads you removed and carefully! scratch the top layer away until you see the copper where you can solder onto. It is the same method that wermy used to modify the original board of his Gameboy in the video.