Removing rubber spare tire kit spacer?
 

I'm in the process of selling my spare tire kit to another rx8club user.

I was reviewing the installation instructions to make sure that I had all of the parts ready for sale, and I noticed the rubber spacer.

In the installation instructions, it's riveted to the chassis.

For everyone that have sold these before, how do you remove it?

I'm suspecting that this is an optional part and the spare tire kit can be installed w/o it, but I wanted to make sure so that I don't rip off they guy that I'm selling it to.

thanks