Yes, but it's not easy. If you don't have the Unit and Base Repair manuals you'll find them very useful! Fuel tank removal is in Chapter 3 of the Unit Repairs EMER (Trk E103/3).
Don't disturb the cables going to the fuel tank sender unit you can see behind the driver's seat! MAKE SURE THE TANK HAS BEEN DRAINED - the lifting eyes aren't designed to carry a tank with fuel in it. Remove the plates to the bottom left of the driver's seat (one carries the engine disconnector cable). That will give you access to the two plugs carrying the cables for the fuel sender and pump. If the self-sealing fuel couplings are still in place you can undo them too; they may have been replaced as they tend to leak with age. Remove the hull plates over the top of the tank, the vent pipes, angled support members and the battery tray. Undo the cable clamps securing the tank and lift making sure that nothing gets caught on the way out.
If you want to fit an oil pressure gauge there's a tapped hole on the crankcase next to the oil pressure switch. It will be a pack out job to get at it, though.