This step will require the cutting of some bricks. We show bricks being "broken" to the correct length with a brick hammer, this is something that takes practice, you can try it but be prepared to break a lot of bricks into unusable pieces. Even and experienced mason will lose some. If you don't have enough brick or are worried about losing too many you should rent a brick saw from a contractor supply. Talk to the folks there and they can show you how to use it properly. Follow all safety instructions. Measure the distance from the outside edge of the column to your mailbox and reduce that measurement by 3/4 inch (the width of the mud joint between the brick and the mailbox) cut bricks as needed to finish out your last couple of courses. When you have reached the top of the mailbox, continue with your final course over the top of the mailbox to incorporate it into your column of brick. Finish out your mailbox by adding the top. Add one line of brick front to back down the center along the line of the mailbox, then add brick around those hanging them off the edge approx 1 1/2". Fill in the top holes with mortar and smooth to a finish with your trowel. Now you will need to finish all the joints using a jointer. Fill in any holes in your joints with more mortar now. Use the jointer on each vertical joint and then each horizontal joint (on the horizontal be sure to joint from the outside edges in toward the center, so you don't knock your mortar out of the joints at the end) Now use a brush at a 45* angle, brush the entire column gently, using a diagonal sweeping motion, and then rejoint to smooth and rough spots. Push the screws of the mailbox flag into a mortar joint before it sets up. Allow to set for at least a full day before use. Enjoy your new mailbox.