Looking for Space Invaders experts.....

How do i open the Front Glass to change lamps?

The glass has a channel-lift rail, and it lifts maybe 5mm up, but not enough to come out.

When i open the entire door, i'm faced with potentially removing the backglass to also get access to the globes.
I can't see any form of lock-mechanism that stops the FRONT glass lifting out.

Any clues before i bust something?

There is a slide which increases the glass clearance on the top when it is pulled towards the back of the cabinet. I will get some photos tonight for you. J.D>

Marty.