To install unzip and place this script into the following folder:
Preferences -Startup Scripts
At the bottom click the "Reveal Button" this will open the folder where the script should be placed.
Close and restart Bridge.
Accept the new script.
Select the documents you want to target.
Tools - Find and Replace.
The "Replace" field is where you enter what you want to find
The "With" field is where you enter what you want it to Replace.
N.B. If the "With" field is left blank the characters will be removed.
The Global checkbox will let you replace more than one occurrence in the Description