fuel pump replacement

Hi, I have been watching your excellent video on how to replace a fuel pump, thanks for posting.

My car has been in my garage for around four years since it broke down. back then I had a mechanic look at it and they told me it was maybe a cylinder head issue.

One month ago I had a mechanic come and replace the battery and diagnose any problems with the car but we could not get the car started. mechanic informed me this would be the fuel pump and did some tests to prove it which made sense.

So to replace a fuel pump costs £350 minimum in London where I live, so I have decided to do it myself.

I have bought a jack and four jack stands and now the car is elevated about nine inches off the ground. So I have a few questions (if you have time to answer them I would be very grateful!).

Is the elevation enough to "drop" the tank?

What safety issues should I be aware of (disconnect the battery, fuel lines etc.)

Also, today when I turned key in ignition all I hear is "clack clack clack" whereas before I was hearing a fairly normal ignition sound minus the fuel pump sound. Would this be an issue with the starter motor? could I have done something to car when I was using the jack?

Any help much appreciated, cheers!

Ed from UK