How to shorten a Refractor tube?

Yes, this sounds crazy. I have an Orion 80mm ED scope that I want to use for terestrial viewing. With the 2 inch Williams Optics prism diagonal that I purchased, I do not have enough "in" travel to bring all of my eyepieces to focus. So how would you go about this with a minimum of expense.

Thanks,
Doug

I've been wondering the EXACT same thing for the same combination! A buddy told me to put tape around the outside of the tube and very carefully cut the tube with a fine hacksaw... I'm not so sure about it.