AppleScript to remove a common prefix from the name of all files in a given folder.

remove_prefix.applescript

set path_ to (get path to desktop as string) & "FOLDER NAME HERE"
set prefix_ to "PREFIX HERE"

tell application "Finder"
	set dir_ to folder path_
	set files_ to items of dir_ whose name of it starts with prefix_
	set start_ to (get length of prefix_) + 1
	repeat with file_ in files_
		set oldname_ to name of file_
		set end_ to length of oldname_
		set newname_ to (get characters start_ thru end_ of oldname_ as string)
		set name of file_ to newname_
	end repeat
end tell