It depends on what time frame you have to transition this from logged ground to pasture.
I am doing a bit of the same thing. I need more pasture and less woods. My plan is to work along the edges gradually taking out trees myself. The wood is sold for logs, tops are sold for firewood and the slash is chipped and either spread and disced or used for bedding, landscaping, etc.I bought a stump grinder to get the stumps below soil surface without massive soil movement. My plan is to add a couple acres of pasture per year this way - depending on time available.
If you want or need to get it done in one year you will have to go the high dollar route with big equipment. It may be worth the investment of dollars, or it may not. Depends on your situation. I feel that if you ahave a couple years to transition the 60 acres you should buy a tractor mounted stump grinder and grind stumps as you have time. Maybe grind a couple acres, then disc it smooth, soil test, lime and fertilize as required, disc it again and plant. I wouldn't worry about a few limbs etc. A good heavy duty flail type orchard mower will chip them pretty fine and leave them in place. Or if they are larger, a tractor loader with a log-grab or other equipment can move them to a ditch and burn the pile when it is safe to do so.
You can do most of this yourself but again it depends on your own situation, time and money available etc.
The other approach is capital intensive but faster. Best of Luck.
Another thought is to just clean out some areas and let the cattle graze other overgrown areas until you can get there to clear them - as long as they have enough to eat the cattle don't mind the stumps.
