you want to fill it with soil, good soil, ph 6.5 to 7.5, and make a little well for the root, and bury her to her neck...i go about an half inch to an inch down from the leaves..you can keep doing this every few days to strengthen the root until they are ready for bigger and better...

have fun

ps...i dont personally think there is such a thing as a pot that is too big...the more room, the more oxygen for the roots....this is a good thing...