How to Hack Gamerscore using Xbox 360 Profile Editor
What you will need:
Data Migration Kit (free) (or XSATA/ X-Port/ Transfer Kit)
Xbox 360 Profile Editor 2.5 (WORKS WITH ALL DASHBOARD UPDATES)
Xplorer360 (Click to Download)
.NET Framework 3.5 SP1 (If you don't already have it)
How to do it:
Connect your HDD to your computer using your Data Migration Kit
Open up "Xplorer360"
Click "Drive> Open> Harddrive or Memcard"
Navigate to "Partition 3> Content> [Your Gamertag ID]> FFFE07D1.
Right click on your profile and click "Extract". Yours probably won't be as big as mine (19MB), but they always start with an "E". If you are having trouble finding your profile, delete old profiles from your 360 that you don't use.
Save your profile to your desktop or anywhere you'd like. Leave "Xplorer360" open.
Open up "Xbox 360 Profile Editor"
Click "File> Open" and select your profile that you just saved
Now you should see a screen like this after it loads your profile:
Now using the scroll bar on the left side, select a game that you want all 1000 Gamerscore in. I'll be using "Blue Dragon", because it doesn't have any online achievements, therefore decreasing my risk of being banned.
Click the "Online" or "Offline" box, and then click "Set" to unlock achievements individually. Click "Unlock All" to unlock all the achievements for that game. Note that for online achievements, you can select the time it was unlocked. This can be used to make it look more legit.
Do this with all the other games you want. I'm warning you again, don't get too excited and overdo it. Before you continue, remember that you could possibly get banned. Don't do too much at one time.
After you've unlocked all the games you want, click "File> Save"
Now go back to Xplorer360. You should still have the window open, like I said earlier.
Now click "Edit> Insert File". Select your profile that you just edited. Click "Yes" when it asks if you want to overwrite.
You're done! Now plug your HDD back into your 360 and see if it worked.
Please post if you have any questions or comments.
If Xbox 360 Profile Editor won't open or is giving you errors, try downloading the latest .NET Framework and running the program as an Administrator.
If the Gamerscore isn't showing up on Xbox.com or your friends can't see it, try recovering your account. It seems a lot of people are having this problem.