The Mégane II Owners' Club

I've been tasked with "helping" my son replace a duff switch.You all know what that really means!Anyway we've located the switch.Bought the new one.I've got the correct spanner, jack etc.But,I can't for the life of me figure out how to detatch the wiring from the old switch.I've squeezed and tugged as hard as I dare ( missus ) to no avail.Can anybody let me into the secret please?
Cheers Alan.

I don't know that part in any depth, but most connectors have a small plastic lug that needs to be depressed with a small flat screwdriver.