So I have an under house shed area, where there is a sloping Clay Soil bank and an uneven Clay floor.

My end goal is to turn this area into a space that can be used for a general woodworking/workshop type space.

In order to achieve this end goal, I'm wanting to dig back the bank to an even depth (to increase the floor space), then add a small retaining wall (under 1.2m) to control the clay debris and create a storage type area. I then want to flatten the floor area, so I have a decent base to lay some sort of false floor on which to work, probably using something cheap like pallets as a base.

Issue is that there's no way I'd be able to get an Excavator into this area as it's at the rear of the house, there's quite steep access and it's technically inside.

The bank is around 10m long and I'd be digging back between 500mm to 1000mm, meaning there's around 9m³ of clay to dig (and probably a bunch of rocks), and while I'm sure I could just start attacking the bank with a shovel, I'm not exactly keen on semi training for the Olympics if there's a smart way to handle it.

As for the floor, I had thought of using something like a Rotary Hoe to break up the compacted clay, levelling it, then recompacting, but unsure if this is the best way.

Any ideas people might have?