Ok whats the easyest way to test for a few leak?

Want to see if I can find leak 1st before I jump to pullin tank out..

Light a match .....

Seriously ....I guess you'll have to pressure test the tank ....which woud envolve capping the inlet and vent ....then pressure from the pickup side ...I would not think much pressure ....8-10lbs? somone will know ...m