If you're careful, you can remove your old fireplace mantle and replace it with a new one. Here's a quick run down of the steps you'll generally need to take to do this. Your procedure may vary slightly depending on how the mantle is anchored. Don't forget to wear safety glasses while doing this procedure. There are any number of chances for chips and splinters to fly.
1. Use a prybar, hammer, or painter's tool to remove the trim.
2. Use a prybar and/or hammer to pry apart the pieces of the old mantle. Once the trim has been removed, it should be obvious where the joins are.
3. If any part of the mantle is set into the brick, loosen those parts by tapping on them gently with a hammer and pull them out.
4. Seal any holes left by this process so that the wall will be tight and weatherproof again.
1. Compare the size and shape of your new mantle to the space the old one left behind. Find blocks to fit too wide openings or chisel out extra mortar as needed to ensure a good fit.
2. Insert replacement bricks to plug the holes. Spread mortar around the edges of the opening and put replacement bricks in one at a time.
3. Take a 2x2 ledger board and use a level to position it. Mark mounting points (two is all you need) where the board meets the mortar joints. Check again to make sure the board is level.
4. Drill holes through the 2x2 where you marked it for the mounting points.
5. Use a masonry bit to drill holes for lag screws
6. Position lag sleeves into the holes and set the ledger board in place. Check it again with the level before using lag screws and a wrench to secure it to the wall.
7. Place the new mantle on the ledger board and nail it in place.