honestly, the oksu one didnt have any sort of application process. I filled out a basic registration form (i think it was a one sheeter) and emailed it in and then called like an hour later (wanted to make sure they got my form before calling) to pay for the class and they sent out the course guide the next day.
Here's the link to the course description. It says its $671 on that page, but I think I remember it being a bit more than that, but I don't think it was too much more.
If at all possible, double check tomorrow with whatever school you're applying to to make sure they accept the oksu course, unless they have already said on their website they accept it (or if its oksu obviously lol)
The oksu one you could finish in under 2 months if you were motivated. I did most of the course just this month because I got lazy and procrastinated (and then have currently put it on hold for now bc I got into a different school that doesn't require it but I'm still planning on finishing it, just at a slower pace) so it definitely would be doable to finish in two months. None of it is watching lectures though, just reading the course guide and book and answering the assignments and then taking the tests.