They're at Kirkdale Learning Centre on Kirkdale, just past the Fox pub. Monday evenings (not sure of time) and Tuesday mornings (10.00-11.00). This term finishes in July and the next one isn't till September. I don't have a phone number so you might as well just call in, tonight if you get this messge in time. You might be able to join now perhaps? I don't know what the rules are about taking the place of someone who's left - there is sure to be someone. The number will be in the phone book.
Good Luck.