The answer is that you can't.
Take a look at where your RAM is on the board, when the case is shut. There is not enough clearance for a larger bay. Even if you were to dremel a bigger hole, and make a new mount, you wouldn't be able to have any RAM installed, and have the case shut. That is, unless you came up with some sort of crazy scheme to move the RAM (far easier said than done, I don't expect to see it wink ) :P