Despite best efforts, it is almost a certainty that one home improvement project in your lifetime will result in paint being spilled on your carpet. Unfortunately, getting latex paint off of carpet is no easy task. However, with a little patience and good old-fashioned elbow grease, it usually can be done.
Mix a solution of warm water and non-bleaching liquid detergent. Put a little of this solution on a clean cloth, enough to make it damp.
Blot up as much paint as possible using the damp cloth. It is important to simply press down and blot, taking care not to rub the paint as this will make the problem area larger.
Rinse the cloth with fresh water, and repeat the blotting process to see if this will be enough to remove all the paint. With small paint spills, this may be all it takes.
Repeat the process with another cleaning solution. If the water and detergent solution did not remove the stain, you can also try a specialty cleaner like Goo Be Gone, Simply Green, Awesome, Oops and Lift Off. Using hydrogen peroxide, rubbing alcohol or nail polish remover may also work, but be sure to make sure the carpet is color-safe before using as not to discolor the carpet.
Try a carpet cleaner. If the paint is not being removed by hand with cleaning solutions, a steam-based carpet cleaner may do the trick.
Remove as much of the paint as possible while dry. Try carefully using a butter knife or dull pair of scissors to remove the dried paint from the fibers of the carpet. If it would not damage the carpet too much, you may also want to consider using a razor blade or scissors to cut off some of the carpet fibers that are completely saturated or clotted with paint.
Vacuum the area as thoroughly as possible. Make sure to go over the area several times with the vacuum, until you are satisfied all of the paint particles that were loosened were sufficiently removed.
Use a commercial latex paint remover. However, before applying it to the paint stain, make sure that it will not discolor your carpet.
Call a professional. Dried paint can be much harder to remove than fresh paint, so if your efforts do not result in the stain being removed, it may be wise to seek professional help to clean the area.