If your mailbox flag has seen better days, has become brittle, faded or broken off entirely, then it's likely time to replace the flag. Luckily, you can find an affordable replacement mailbox flag at almost every hardware or home improvement center. Once you have your replacement flag picked out it should only take a few minutes to install the mailbox flag and be ready for your letter carrier.
Remove the old mailbox flag from the box with a flat-head screwdriver by slipping the screwdriver in between the outside of the mailbox and the flag block. Pull the screwdriver away from the box to pop the clips off of the block.
Place the new flag block against the right side of the mailbox. If there is a slit in one corner of your flag block, rotate the block so the corner with the slit is in the upper right. Align the block so the holes in the corners of the block are paired with the drilled holes in the side of the mailbox.
Put your hand inside the mailbox and put one of the four clips through each hole of the mailbox and into the flag block corners. Push each clip until you hear a click or pop.
Hold your mailbox flag either directly over the center hole of the flag block or, if a slit is available, insert the end of the flag into the slit. Align the hole in the flag to the hole in center of the flag block.
Secure the flag to the block using the attachment unit from your kit, either clicking the unit in place or using a wrench to secure a nut to a bolt. Replacement flag kits work differently depending on the manufacturer, so follow the directions on your packaging for understanding how your particular attachment unit works.
Test the flag to make sure it goes up and down smoothly. When the flag is up it will need to be tightly secured so it won't drop if it is a windy day. Tighten your attachment unit, if needed, to make the flag more secure.