Which roots to cut in mini-phal repot?

[jmain3]

Hello! I'm an orchid newbie. Proud of it! I'm trying to repot an orchid I got on clearance at Lowes. I've taken good care of it, and have encouraged new leaf and root development.. But, it needed to be repotted. My question is that I'm not sure what roots to cut? I don't want to over cut. All the roots are not soggy or moist. All but the new ones have black or brown spots which worried me. It was just a $1.00 purchase so I will not be too upset if it is a loss from your opinions of the pictures from this website:

https://picasaweb.google.com/sixshoo...eat=directlink

I also attached photos.. In case they show. First time poster! I thank you dearly for your time in reading this and assisting me with the little guy. It's a miniature phal.

--Jenny