Any tips on removing the emissions control valves from the fuel tank?

[Black Cobra]

I got a new 03/04 Cobra tank in today. The old one is over 9 years old and is heavily corroded throughout. Maybe a 1/16" of rusty sludge coats the entire inner surface.

I've got a post into Tousley for new parts; but just in case...does anyone have any tips for removing the plastic emissions control valves off the old tank without damaging them?

Thanks.