Dismantle Stoves Farmstyle range cooker?

Hi,
Sorry for my first post to be a question, but now that I’ve found your forum hopefully i can be of some help to others.

I have a Stoves Farmstyle 1100 range cooker and need to test/replace the knob for the grill. I’ve had it in bits before but can’t remember how to remove the strip in between the two stove tops. I recall it slides to the front somehow but i can only move it about half an inch before it hits solid. Any help welcome 🙂