Your string height is going to raise a little due to the additional tension. If you want it where it was, before to take off the 9's, measure the string height at the 12th fret - bass side and treble side.
Put the new strings on. Measure again. To lower, simply drop the bridge til you get it where you want it. Might need to lower the tailpiece a bit too.
If you don't mind the strings a bit higher, no other adjustments are necessary. If you went from 9's to 11's, you might need to have the truss rod adjusted a bit - much more string tension than 9's to 10's.
