There may actually be two pumps (it's been a while since I've seen under a VR V8 but it certainly applies to VN); one external to the tank and one internal. The internal pump feeds fuel into the external pump.
The external pump will be an Al. cyl., under the car in front of the fuel tank, about the size of a drink can. It will have rubber hoses going back to the tank (front of the sender unit) and leading forward to a metal pipe that runs under the car to the engine, via the fuel filter. If it has been replaced it should be obvious - clean etc.
The fuel filter is a smaller metal can, located as ^.
The internal pump will be mounted in a bracket inside the tank that is integral with the fuel gauge sender (fuel level measuring) unit. The outside of sender/bracket can be seen on the front of the tank; about 80mm in diameter, with bolts holding it in place.
There are a couple of things in that bracket that could prevent the fuel pump from operating:
One is that (one of) the fuel hoses aren't connected inside the tank - as per wateva ^^ - but the pump should still run (for a while) if that is the problem.
Another is that there is rubber sleeve that connects the pump inlet to the sender assembly and that needs to be in place and not pushed back along the metal pipe or damaged. The pump will also run with that, just not deliver fuel.
It is also possible that the wiring inside the tank to the pump has broken, inside the insulation, which would stop the pump from running. As the wiring is part of the sender assembly, that may be why the mechanic was suggesting that the sender has to be replaced.
If the oil is clean - straw coloured on the dipstick, easier to see if dripped onto a clean sheet of white paper - that would indicate that the oil has been changed, black if not. The oil filter you would have to look at.
They wouldn't have to remove the wheel to change a fuel pump or filter, nor change to the engine oil. Even a brake pad wear check may not need the wheel removed.
I'm not sure what you found with a search on here but swapping the sender/internal pump is indeed pretty straightforward but messy, potentially dangerous (fire risk) and you do need to have a jack and wheel stands to get the back of the car off the ground. Also, somewhere to store the fuel that is currently in the tank.
Any time the sender is removed you should replace the cork gasket and probably the strainer on the fuel pick up in the tank. The bolts (only) need to be sealed with threadlocking compound eg. Loctite 242 applied to the threads before they are reinstalled (clean and dry them prior to application, both tank and bolt threads).
