I think I know the type...I have worked with those things twice that I remember..and it was ruff both times. The front does have to come..and then there is some release mechanism...but I cant remember what it is.
Is it possible that there are two things that have to come off of the front??
Not just the little colored thingy...but then another piece?
Also, look along side the metal frame of the case with the side cover off...look for little diagrams with arrows etc.
I cant remember specifically, but its easy once you figure it out....and the drives do slide out the front.