first make sure all gasoline has been removed from tank, hoist entire car w/hydrolic lifts or park over a 6 ft deep trench-walkway(like in a shop), then use a water based cutting torch to cut along the top of the tank underneath the floor board of the car. If you're changing the tank all together but still keeping the car& refurbishing it; you've got your work cut out for yourself 'cause a suzuki isn't worth really keeping anyway!! Sorry pal (you will be able to tell if the switch is turned on cause there will be pressure in the line) un-hook the line so you'll know for sure; preferrably when the car isn't running or without using safety precautions first---ask a mechanic(a real mechanic)