How do I remove brick that has been used as a backsplash.

Not sure this would work, but you might get some kind of grout to fill in the grooves to make a smooth surface, (ask at home store for advice) and then apply something over it...peel and stick, paint...tile?

It sounds like it might be a brick veneer. Brick is porous and usually not to hard to remove. Get a thin smaller (18" or so in length) crow bar to work under one brick with the flat edge and carefully loosen- keeping the bar parallel to the tile. Use a rubber mallet to hit the bar end. Remove one row at a time.

If you work slowly and figure the best way to remove them youll have a decent surface for something else.

Don't worry about the plaster because it will likely need a skim coat of plaster. Keeping the bar flat against the brick back will keep the lath from breaking up.

Paint it?

You could milk or chalk paint it. There's a DIY on this site to do it, the results look great!

Unless you know what you're doing, plaster is difficult to repair. I would talk to the pros at the home store or hardware store for options but paint really does work miracles.

thank you all for your help. These are all good ideas and I will start in a corner not really seen, just in case I goof up. I'm sorry for the misspelling in my post. Not sure if it's my computer messing up or my fingers. lol. I will post my results as soon as I can.