Trouble with adding clan tag to profile

To add or change a clan tag log into battlelog.battlefield.com, click on your profile in the upper right hand corner, then in the top center there is the option called "Edit Profile".  Click "Edit Profile and in the center of the page under "Soldier Settings:  Edit soldier image and clan tag" there are boxes next to each of your soldiers, you can add your clan tag.

Also be sure to allow flash to run so Battlelog can run properly.  If you have flashblockers, script blockers, or popup blockers active Battlelog may not allow the clan tag to update.