Repotting my Phal Amabilis

[ladyslipper]

I have just bought the amabilis & the grower told me that I should repot it by next year or risk losing it. It is currently in spag moss but when I repot I am going for med bark because I like the drainage better. I am also changing the plastic pot to a plastic orchid pot for the drainage benefits. What I am writing about is help for the repotting. I am scared I am going to kill this plant when I repot it. The grower told me I don't need to increase the pot size but need to refresh the medium as it hasn't been repotted in about 2 yrs. The plant looks like it is trying to escape the pot so when I do repot, do I put some bark in the bottom of the pot then (sort of) push the plant back in the pot then fill whatever space is left over with the bark? Should I gather the roots or sit the plant in the pot & let the roots go where they wanto to. How about any fertilizers (all plants get a weak fertilizer at the beginning of the month)? Any information you can give will be greatly appreciated!
Regards, Mary