Classic/Antique Car Repair: 1986 Jaguar XJ6 Fuel Transfer Switch, jaguar xj6 fuel, 1986 jaguar xj6

Question
How hard is it to change this switch, where is it located, and can this prevent the car from starting?

Answer
I'm sorry, but I am a Model A guy and don't know a thing about the ag.  I don't know what a transfer switch does.  Maybe from one sode of the tank to the other.  If it does something like that, keep a high level of fuel and it should not matter.  Find a Jag car club and join it if you have to.  They would have all the answers.  If you can get a service manual for your car that would help you for this problem and future ones.
Good luck.
jack