Are you trying to remove the plywood sheet Sammy, or just slide it and the tank/cabinet to the left?
Either way, it's probably a three person task - two to take some of the weight off the ply, and a third to push the ply along.
According to EA, the AS900 tank is 42Kg, the cabinet is 45kg, and it holds 186 litres (so 186Kg) - 273Kg filled. If you have it 20% filled, that's about 124Kg - a lot of weight, but just about doable between two strong people - they don't need to lift it completely, just take some of the weight whilst shuffling in the required direction whilst the third person pushes the plywood.
If you are on a flat flooring (laminate/wood etc) it should be okay - if you're on a thick pile carpet you're going to have more of an issue, especially if you don't want to create a ruck in the carpet.