I'm not doing ACCA, but i'm doing CIMA, which is very similar.
I do it part time, while I work at home. I just applied at a local college, and it do it when it suits. If I have got a lot on at work i'll only sit one exam, but if i've got a bit more free time i will sit a few more.
Its quite easy to accomadate your needs.
I'm guessing ACCA will do the same, check the website out!!