Element?

Rangemaster Leisure 55 - Serial 5462 001 760

Hi, the grill hasn't been fully working for a while and I have looked to change the element. When looking at the top of the grill it looks like a corrugated metal roof which I am presuming is not the element? Can I unscrew this and is the element above it, or is the corrugated metal the element? Any help would be great so I know what part to order. Thank you