I recently checked my '80 300TD tank screen. I raised the car on my homemade wooden ramps and removed the hex socket plug with my biggest Allen wrench shimmed a bit bigger. It came out easily. I noticed a pretty big cut on the outside of the plug where somebody apparently had tried to loosen it in the past with a cold chisel. I had prepared a plug made of a golf ball wrapped in a sock, covered with a plastic bag. This was pushed up against the hole as soon as the tank plug was removed. Lost about a cup or two of fuel, which was caught in a shallow plastic pan about 12" x 15". This was done with the tank nearly full of fuel, mostly WVO. My son then slid some wooden blocks under the tank and we held the golf-ball device in place with a 12-ton hydraulic jack. I was pretty sure that would be adequate. The screen was found to be perfectly clean. We reversed the procedure to replace the screen. Total fuel loss was less than one quart, which I recycled to my WVO filter in the back yard.