if the plants are live, go around them and gently so you dont crush the roots. Lift or remove the other decorations and vacuum the gravel.
PS
You do not need to change the water to rid of ick. Simply crank up the temp to about 82 degrees by turning the heat up one degree a day so to not shock your fish, and leave the heater at 82 for a week or longer to speed up the life cycle of the parasites, until absolutely no signs of
ICH remain (no white spots, no flicking, no labored breathing, etc...). Use the same method to get the heat back down to normal temperature after treatment.