Getting ready to do a job that's going to have 6 ground rods according to code. 2 at the main service, 2 at (1) accessory building, 2 at another accessory building; all on the same residential property. Glad I've got my trusty rod driver on my roto drill:)
We had a 6" pc of 4" PVC cuts at each location, used orange spray paint, and documented each location on the site drawings. Removal was not really that bad, using the Lull forklifts, a web strap, and a Klien line grip (Chicage Grip) that nicely fit the 5/8" rods. Got them all out within a ten day total period of the teardown. About 50% were 'salvaged' to the event contractor for re-use somewhere else; the rest were mangled and trashed.
The complete teardown (electrical) was completed in 21 days.
I bought a Bosch electric demolition hammer way back when I was in business and I also bought a ground rod driver. It would drive the ground rods in with ease. In some of my towns. Where the ground was soft and/or had some rock. However where I live, it is almost all rock. It is almost impossible to get a ground rod down 8' every time, on the first try. You would have to stop and pull it out and try again and again. sometimes you would get it down 7' and you couldn't get it out anymore.