Robosapian V2 to Hexapod conversion, is there a solution to the microcontroller problem?

I've come into possession of Robosapian V2, I quickly became bored with it as I was not happy with the robots ability to move, while the robots sensors and brain is nice the field of motion is lacking and awkward so decided to rebuild the robot. I removed all of its components (sensors, motors, and controller) and converted the machine into a Hexapod (lovingly called Jinx) and have now come across a problem originally thought simple now becoming annoyingly frustrating. The brain.

I was just wondering is there a way to access the software to reprogram the robot how to walk.

Or if reprogramming the robot is too difficult is there a way to have the sensory information be sent to a computer and the computer sends back motion commands over a medium such as wifi?

an instructable of the robot will be released once I’m done with the robots rebirth and special thanks to anyone that has helped will be given thank you

i live in Australia and Auduinos are not only hard to get but pricey, my financial situation isn’t that great as I am 18 and only have a part time job but do not mind spending a bit of cash. Also I am good with electronics and software just finding this problem difficult