How do I set up an ABLE Account

It looks like it depends on your state government to allow them (most do). I would start by googling “[your state name] able account”.

I did so for Washington state (just an example, since you don’t say where you live) and found washingtonstateable.com, which has a link to open an account.

(Edit) Or just use the link posted in a comment above to find your state’s program: http://www.ablenrc.org/select-a-state-program/