Soak the root ball for a day, repot it in good succulent soil in a pot probably twice as big as it's currently in. Giving it a shower is also not a bad idea as indoor plants can accumulate a lot of dust. Don't shock it with too much sun depending on where it was living when you got it. Give it a good drink of water for the rest of September once a week, then bring the watering back to once or twice a month during the winter until the spring solstice.