I'd pull the tank and have it boiled and sealed (or replaced), and I's also get a new pick up, fuel pump, filter, and rebuild or at least drain the carb and clean it. If you don't you might be chasing bad fuel gremlins forever, I hear it A LOT from my customers who've tried to cut corners.
.02
That's right way to do it.
The dirty way is an electric pump with fuel lines connected. Pump out as much as you can and then put in a can of Heet and some fresh gas.
