I just bought my son a power wheel jeep wrangler and I would like to make it remote control forward and reverse and the steering
You’ll essentially be hacking the power wheels, and you need to first find out how it works. Open it up and try to get a good understanding of the motors, controller, steering etc. before adding, removing or re-wiring parts. You’ll also need the specifications of the motor(s). The basic procedure would be to first try to reuse the motor controller included with the product, and if not, replace it with something which accepts external input. As for the steering, most people tend to use a servo motor connected via pulley. We encourage you to include photos here, and what you find in terms of specifications.