How do you remove the cover of a Hitachi MCB30 Microwave (Bulb Blown)?

The light bulb has blown on my MCB30 Microwave. There is no visible way to access the bulb from the inside or outside other than by removing the cover (With the unit unplugged of course). Some of the screws are Phillips others are not. I have tried T10, T15, T20, H2, H2.5 and H3 Screwdriver bits on the others, none of which fit.
Am I going the right route via the cover?
Does anybody know what type of screwdriver to use?

Rob T
July 2010