Backyard Sod Replaced with Pea Gravel

I have removed the sod from my backyard and am looking to replace an area of about 15x'15' with pea gravel. How much should I be removing of the existing clay soil, what is the easiest way to remove it? Also my idea would be to put down limestone screening, tamper it down, lay professional grade landscape fabric, then the pea gravel. I also know I need to put in some edging to keep the pea gravel from travelling into the border garden.

Any suggestions appreciated. Removing the sod, even for this small area was alot of work. The ground is so unlevel and also has a gradual slope so hoping it isnt going to be too much manual work to dig it up to level