Have you read the documentation for those tools? Have you researched all the threads about them?
Blindly trying to edit files without knowing why you are doing it won't lead anywhere.. Neither will using those tools without knowing how they work...
The dev klic might already be in the dev_klics.txt database from aldostools. If not it needs bruteforced.
Look at zecoxao's explanations here
http://www.ps3hax.net/showthread.php?t=61533
Look at step 3. Not a step by step exactly but the goal is clear. Use the dlc rap file to decrypt the edat then reencrypt it with free dev klic.
Also please read the posts following the OP, many questions are answered there.
Check the psx-place threads about aldostools & jikkyu's tools, most questions have already been answered.
Note that if the DLC was not obtained legally & you are missing a file or something has been patched already, I cannot help you any further though...