I'm not much of a garden type person either, we bought a ficus for our chams cage 2 feet tall for 5 bucks at superstore. I dont have a clue what they use on their plants there but this is what I did with it...
*others feel free to correct me if this isnt 100% safe like I said I'm not a gardner and I'm new to owning chams*
I put it in the shower turned on the shower and soaked the plant (roughly 5-10 mins) then I washed the leaves and branches.. teadious but I wanted to be safe, I didnt re pot it. I dont have any new pots to put it in and I didnt know you should have done it oops hehe
I let all the water drain from inside the plant, and dry. I think it was in the tub for a day or 2 ... after this I took screen and covered the top of the pot and secured it around the base of the tree, oh and I also put rocks and marbles in the dirt under the screen to stop crix from trying to breed in it *i feed free range*
I hope this helps you out a bit, wait to see what the experts say though lol because I'm not sure if this method is totally safe but its worked for me.
cham_paradise also has a link - find on of his post scroll down goto the one about cageing baby chams he had some info in there about replanting plants and making cuttings from plants (dont know what cuttings are you will after reading this lol) to make things easy scroll down till you see option #2 of plants for your cages it tells you about re potting - which I suppose it the proper way you should really do it.
okay enough blabbering... good luck with the plant
Christa