I did two last night and I'll do another two tonight. Big bucks if I take them to a shop and no guarantee on quality, It is way worth it. As already stated by others, proper tools are essential, although my iron isn't perfect but it worlks fine, and start with a board you are least attached to. Practice on it three times before you tune your babies.
This link here, http://www.alpinecarving.com/tuning.html , really helped me out a lot.