Port Installed Options

I am looking at buying a new Nissan Xterra 4x4. I have searched the deaership websites in my city and I have found a few I like but some have extra port installed options that I don't want.

I understand dealer installed options but what is a port installed option?
Is it possible for the dealer to remove/add port installed options?

There are few 4x4 Xterras in colors that I would actually buy so I want to know if I can expand my search by telling the dealer to remove the options that I don't want.

Thanks for all your help.