Before you stabilize (I assume that's what you meant by "powders", you have to rack off of the sediment. Otherwise, fermentation will just restart.
To do that, dissolved the stabilizers in water (usually it's 1/2 teaspoon sorbate and one crushed campden tablet per gallon). Pour that into the receiving carboy and rack the wine into it. Wait three days, then sweeten to taste. Wait three more days (to ensure fermentation hasn't restarted) and then bottle.