Dig some trenches to level a trampoline on a hill

We have a trampoline that we’ve just moved in and we need to get it level and safe for the kids to jump on. To do this we need some trenches dug at the deepest about 20-30 cm and level so that it can then be secured to the ground. It only needs 4 trenches about 8 cm d Wide and a meter long. On 3 sides. Straight forward and easy