Tkx so much.

hummerz thanks for posting the YT videos, really helps with visualization. Is it necessary to have access the pump via the rear wheel arch?

No, that's a New Yorker thing, you will also notice a folding chair on 1 end, and a bucket and step stool on the other end. :confused:
If tank is close to empty, you can simply remove a strap while holding the tank, then drop it down a few inches on to a secure platform, go to the other side and do the same. I use hydraulic jacks with plates on jacks, to hold it steady and lower it. Now you have access to remove the lines and connectors. After everything is disconnected, lower it to the ground and go to work with fpm removal, tank cleaning, and new install.