How do you get it off? Then after its off how do you put it back on? Because I need to put the chrome piece on it and it needs holes drilled for the piece to go in.
Thanks.
Oh, and I have a 68.

 

I don't know about the 68's, but on my 65 the rear quarter extensions are held on by 3 bolts and nuts. Look inside the trunk right above the tail light and you should spot the nuts that hold it on if it is the same configuration as a 65.

 

yeah they are all the same.