I have a Curve 8900.

I've replaced my trackball a number of times with no problems, however lately it hasn't been clicking.

I just received my order of domes today to attempt to remedy this problem.

The problem I'm having is they will not stick. Where is this sticker part? All I seem to have is the tiny little copper piece, but nothing to make it stick in place.

I put it in hoping it would stay there but after moving the phone around a little bit, it dislodged so now I'm back to where I was.

Can someone please explain this to me. Thanks.