It should be an easy thing for you to do, just drop it down and swap the old stuff out of the old tank into the new one?

I have actually not done it on the monty though, but many other cars, it's not hard. Hope fully some other guys might have monty specific tips for you.

John Pszenyczniak
67 Mustang Coupe
95 Firebird Formula
05 Ram hemi 4x4
91 Montero RS LWB w/ 320k miles before rebuild, 900 down and its still kicking!!!