Gas Tank and Foam

[drj]

Hi guys
I am redoing my V-20 and i have the gas tank cover off. I see that you guys recommend removing the foam. I want to do it how should i remove it with a scraper? Also where my ender is a screw hole has corroded. I was going to clean up the tole and plug it with some marine tex and just us a sheet metal screw to mount the sender.
What do you guys think
thx in advance.