How do you fix a washing machine that wont spin?

It could be the transmission or the belt.

Many washing machines, while having different manufacturers, work on the same principle. For example, I owned a Kenmore machine for many years, and when I had the spin problem, I first checked the transmission. Perhaps the machine's transmission is kaput (broken), or maybe a belt is busted. Try looking at these two things first. Also, make sure that your washing machine is plugged in.

You probably need a pump and motor kit