We would normally just take off the bed on a pickup to access the fuel tank, etc.
Manageable with 2 guys if you remove the tailgate, much easier with 4 people.
Gas tanks on S10's and similar can be tricky.
It's likely the sending unit or seal, but it could be anything from the filler neck to the seam in the gas tank itself.
I've seen failure in just about every area of the S10 fuel system.