Jaguar Repair: 71 xj6 gas tank removal, tank removal, large drain

Question
My son was recently given a '71 xj6.  The passenger side gas tank has been cleaned but the driver side tank has not.  he has tried to remove the tank to no avail.  Is there a way to flush the tank without removing it or how do we remove it.  the bottom fender cover is removed and seems that the only thing holding it is the neck but not positive about this

Answer
Hi Darrell,
I have removed several XJ-6 tanks but not a 71. However, I believe it is the same as the later cars and the neck is a slip in with a "O" ring seal and you may have to remove the filler neck.
Also, there should be a large drain plug in the bottom if you want to try to flush it in the car.
Howard