I moved into a house a year ago that had several hedge bushes growing in a row at one time. Someone had eventually cut them down to the soil and just kept cutting over them. So I did try and dig one up by myself, some of these main roots have to be 1 to 2 inches wide. Any ideas?

There's not much to do if there cut to ground level and you want them removed fairly quickly so you can plant something else . Your pretty much going to have to dig them out there are a few tools out there that can help

Keep on digging!! Go about 1-2 ft. from the main stem and see if you can cut the roots. May be easier there.