How do I remove paint from my brown brick house that was left when my brother painted the trim white?

Did you get a money back guarrantee? Most paint and hardware stores sell a good cream paint remover. It is thick enough to stick to brick and takes several minutes to work. Hose off when ready. Have your brother do it.

Muratic Acid, I Doubt I Spelled That Right But Say It Like It Typed, This Will Take It Off, Be Sure To Wear Gloves, We've Always Used This To Take Paint Of Concrete And Brick,

Muriatic acid will work but be sure to dilute it and try using it on a test area before you apply it all over the brick. The acid removes (and will etch) the top layer(s) of brick and mortar so the length of time that you leave it on the wall before you rinse it off is important. Too long and you may take off too much, too little and you'll be wasting your time. It's also important to be consistent with the dilution rate when you mix up another batch and the exposure time for each area you are working on. BE CAREFUL! ALWAYS ADD THE ACID TO WATER... DON'T POUR THE ACID INTO AN EMPTY CONTAINER..

If all else fails... paint over the old with a color more to your liking.