Removed glass cooker cover, cut off gas - re-attach springloaded fittings?

I have removed the glass plate that covers our gas hob to exchange for a new one... This in-turn, has cut the gas supply off to the burners..

It's a New World 2 glass plate that covers a 60cm 4 burner gas hob.

I am unable to re-attach the plate due to the spring loaded mechanisms in them... any ideas on how this is done? Any help much appreciated... Wife's due to give birth tomorrow and I am desperate to get this sorted asap! Argh!

Thanks, Kev