When the old metal mailbox sticking out of your brick pillar is rusty and needs a face lift, seeing that big stack of bricks you need to pull the mailbox from is a daunting sight. Depending on the way your brick mailbox stand is built, there are several options to consider. Usually metal mailboxes are enclosed in brick and set on a layer of mortar that you'd have to chop into. One option is to replace the front door of the mailbox and leave the existing receptacle encased in brick. For a full-scale improvement, you'll have to get busy with a little demolition.
Check your mailbox and decide which approach is best for you. Replace the front only if there is no real problem with the size or condition of the mailbox itself, or its brick surround. Cut off the old front off flush with the brick pillar using a rotary cut-off tool and install the replacement according to manufacturer instruction. Mailbox fronts can generally be applied with clear silicone caulk and screws that come with the kit.
Line your chisel up with the thin layer of mortar surrounding your mailbox if you are going to remove the entire mailbox. Hammer into the end of the chisel, aiming toward the mailbox to keep damage to bricks at a minimum. Don't be afraid to damage that mailbox, however! You're going to throw it away anyway, so bash it out with glee.
Remove the mailbox once it is chiseled free from the mortar. Gouge away any remaining mortar in the hole with the chisel to make a smooth area for the new mailbox.
Slide in the new mailbox to make sure it fits. Remove it, and trowel on a layer of mortar inside the hole.
Set new mailbox inside, pushing tightly, wiping away any excess mortar with a clean rag.