I had to edge my basepaths last year and I got one of my FFA (Future Farmers of America) teachers to help me. He had an edger in the Ag Shop and we went out there and just used it.
What we did was run a string up the baseline and then measured equally in from there and out from there for both sides and marked the line with paint.
Take the edger down the lines and now you have the line for the path. Now take Round Up (or a flat shovel) and get rid of the grass on the inside of the lines. Just clean up the grass and fix your dirt.
If you have a FFA chapter at your school they are a great resource in working on a field. The guy we had made lesson plans out of the work he did.