Jenn-Air C301 Surface Element

I purchased part WPL Y04100166 (element surface) for my Jenn-Air C301 electric cooktop. The part does fit into the cooktop, however the package contained the surface element, a black metal cap and another metal piece (I assume that this is to attach the black cap to the element). After many, many tries, I could not figure out how to attach the cap. This is needed so that heat is conducted to the center of pots.

Thank you very much for your help.

Arlyne Zalaznick order # 1129807