Tank removal is not hard all I did was put the van on axle stands at the front and the back wheels blocked up on wood, total lift was about 6 inches. Plastic and alloy shields are clips and screws so easy to remove. Tank is held with metal loops that are fixed each side of the tank, have the fuel level as low as you can. I removed the neck of the filler behind the flap, just screws. Then I lowered the tank by undoing the nuts, laying on your back you can support the weight of the tank and drop the tank onto some blocks or a couple of jacks. There is a fair bit of slack on the fuel lines which are quick release to remove. If you think you might be putting the seat brackets back in at some point it might be worth putting the bolts back in place to seal the holes.
Baz