How do you lift up the silver part to slide that piece back under? Thanks.

 

If you can find something thin to stick under the silver trim, it just pops up. I have a trim removal tool; But a knife with a towel over it (so you don't scratch it), will work as well.

 

I don't even need a tool. Mine pops out just with my fingers (get a finger nail under it). It's an MT so your AT might be tougher.

If you can't get it out (or are too timid) then yanking the black (gasket) out all together is an option.