This probably only shows how mechanically disinclined I am, but I need some help here. I just got a new drive to replace the stock drive in my Series 3 but for the life of me I cannot get one of the screws out to remove the drive bracket. It turns but seems to turn in free space like it is not actually connected to anything and therefore does not unscrew. I tried lifting it straight out but when I do that there is resistance and it will not come out that way either. The screw involved is the one on the left hand side facing the rear. Any ideas?