This is not always easy to answer as it's difficult not having seen the property, and for me, hills are something we don't have here. Extra care must be taken on hills as implements can drag a tractor sideways and roll. Work up and down the hill, not side to side. If you have ROPS, wear the seatbelt at all times. No ROPS, no seatbelt.
However, the boxblade should be a very good tool for doing this. Make sure you get one with rippers so you can dig off high spots and then spread with the blades. Experimenting with the top link to angle the boxblade properly is the trick.
Get rid of all the debris/rocks before you do anything. Keep in mind that there may be a lot of roots that will have to be dealt with before you can do a good disc job, the rippers should help with that. If you're having troubles getting through with several rippers down, remove some of them as it's easier to drage one or two than 6 at the same time.
Getting in there and trying is the only way to learn how, but it will happend more quickly than you may imagine.
Here's the order:
Clean all obstacles out (regardless of what tools you use)
Brush hog down the growth
Ensure that roots that can interfere with the discs are gone
Disc the entire area
Level with the boxblade.
Pricing is extremely variable. Find some ads that offer tractor work, call them and tell them you need work done, get prices from them. That should give you an idea of what the going rates are for particular jobs. I usually get $45/hour with a 3 hour minimum when I do something for others. $55/hour for backhoe work. I've heard of $25/hour not far down the road though, so you have to check it out well.
If I've left anything out, or given BAD advice, someone will be along to correct me! Good luck and have fun. John
disclaimer: this information is given for entertainment purposes only. Poster is NOT an expert, and this information should not be misconstrued as proper and safe instruction in the handling of any machinery, real or imagined! /forums/images/graemlins/grin.gif John