don't know about woodchuck but the process of kegging a cider is simple; fill the keg, purge the airspace with CO2 once or twice, carb it the same as force carbing beer. i set and forget at 15-20 psi (1-1.5 bar) in the fridge for 2 weeks, bob's your uncle.
since you will be kegging a sweet cider, as i see it you can do one of three things:
1. try to cold crash the cider mid-ferment at your desired gravity, rack to keg
2. ferment out to below 1.000, rack, +sulfite +sorbate +sugar, keg
3. ferment out, rack to keg, +sugar (or better yet aj concentrate) keep keg cold to prevent fermentation, depends on the yeast strain. fine with most ale yeasts as far as i know. at least with s04 and nottingham
