how long does it take for your letter of permission to get approved? As in, when do they send you a confirmation email for it?

From my experience, no more than two days.

All you have to do is to submit the form online. You have an option of sending the letter out or pick it up at the student registrar in GH.

I submitted one online a week ago...but still no reply yet :(
From previous experience, I got a confirmation email pretty quick...