1994 Toyota Pickup Many questions

Hi, my husbands car is totally old and rusted, but then he loves his car. Everything is falling apart and I tell him to get rid of it and stop repairing it.

The rear anti lock brakes light comes on, how do we fix and repair that problem? Also the battery is brand new, but when you start the car there is a click sound. It's because of the wiring, the metal is rusted, but then how do we change that?

Please answer my questions. Thank you.