Copied this from an article I wrote recently. Hope it helps!
Step 1:
Fill a sink with water (make sure it’s a sink that won’t need to be used for a while). Add 2 tbsp. ammonia, 2 tbsp. vinegar and 1 tbsp. salt. Place the stained fabric in the sink with the solution and allow it to soak overnight. If there are areas where the paint is really thick it helps to scrub with a brush dipped in the solution before soaking it. Launder the fabric as usual in the morning.
Step 2:
Apply mineral spirits to a clean white cloth and rub the area free of paint. Launder as usual once the paint has been removed.
Step 3:
Apply a small amount of Pine Sol to the stain and scrub with an old toothbrush. Apply more Pine Sol as needed and continue scrubbing until all of the stain is gone. Launder as usual.
Step 4:
Spray the stained area with WD-40 and allow it to sit for at least 1 minute. Rub the area with a clean, dry cloth until the stain is gone, and launder as usual.
Step 5:
Spray the paint stain with Windex and scrub the area gently with a soft, clean cloth before laundering.