[Mrmerlin]

this isnt hard,
first tie rags around your wrists to catch any fuel that might want to travel down your arms.

to drain the tank remove the hose from the pump inlet let it drain,
you might consider removing the sender to take a peek inside the tank,

NOTE you could refill the tank with some fuel and jumper the fuel pump at the CE panel to run the new fuel through the system ,
the sender must be refitted for this.

refill with some fuel and drain it again,
there isnt any need to blow out the the lines,
it may create more of a fire hazard than anything,
If at all possible work outside