Ducati 750 ss rebuild

Hi all… I have a 1999 750 SS. UK bike with 7400 miles on clock .1 owner from new. Has been off road for 7 yrs. Have done the
cambelts, new plugs etc. sonic cleaned carbs rebuilt with keyster kits . but no fuel from tank, pump not working, have power in there… but i can’t get the tank flange out…took out all the grub screws… tried hot water on tank …has anybody a hot tip for getting it out???. been a mechanic all my life… an its doin my head in… lol.
ps she owes me 2K…if someone wants to give me my money back… have a 2 stroke triple wanting the
space in workshop…
Cheers Pete