Okay, this is advice, ...noob to noob!
1.)What I would is tip those pots on their sides and VERY GENTLY slide the soil/rootball out of the pot.
2.)VERY CAREFULLY as not to disturb roots too much,remove as much "loose" soil as possible. (Paying a GREAT deal of attention to safety of roots, also in fairly dark area)
3.)Mix a 50/50 pearlite new compost.
4.)Refill pot with about 6'' (or more if neccesary) of new mix.
5.)CAREFULLY reset plant back into pot in new soil, making sure roots are optimally arranged.
6.)Fill sides of bare rootball, bringing the base of your plant up to the rim of pot.
7.)Add 1-2 drops of superthrive to straight water and run full gallon through.
8.)Following day, take a pH runoff test, should be between 6.1-6.9 if I recall correctly.
9.)Start back on reletive nutes. (Obviously small dose)
10.)Hope to hell I wasnt too high when I wrote this advice!

SHOULD get you headed in the right direction:thumbsup:
I am also kinda hopin' to get some feedback myself on this advice from some of our more experienced cultivators!