Requirements:

•A Transfer Cable / USB drive

•Xport 360 / Xplorer 360 / USB XTAFFXplorer

•Le Fluffie App / profile editor 2.0 / 2.5

•That you haven't made a Bungie Profile, and your Xbox Live Profile has NOT been activated with a Bungie Profile

•Modio (Or your choice of Rehash/Resigner)

•An Xbox 360

•Xbox Live Membership

•A Computer


Step 1: Extracting your Profile
Open up Xport 360 / USB XTAFFXplorer and choose your HDD or Memcard. Open up Partition 3, Content, Your Profile Folder(You can check by seeing what games have been played), FFFE07D1 (Dashboard Data - Gamerpics, Themes, Profile Data, etc), and then open 00010000. The file inside is your profile. Drag this out onto your desktop. Refer to a more in depth tutorial if you have problems.

Step 2: Modding Your Achievements
Right now, it is essential that you make a backup of your profile, because lots of people screw this up. Open up your choice of Achievement Modder. I will be using Le Fluffie App, but some may prefer Profile Editor. Drag your profile into Le Fluffie App. Click on the tab on the right that says Profile. On this screen you can view all the information on your profile, including gamerscore, gamerzone, rep, games played, etc.

-At this point in the tutorial you may click the Unlock All button to unlock all the achievements for every game played on your profile. You will see your Gamerscore rise significantly. You can tamper with the timestamps. But it is not necessary to mod Recon-

Click on Halo 3, which will be in the list of games near the bottom. Now click on the Achievements Tab located directly beneath the Profile Tab. Scroll through the list of achievements until you get to the first Vidmaster Achievement. At the bottom, set it to unlocked ONLINE. Set a timestamp on this one, that is believable. I recommend setting the timestamp to the date 7 days prior. Now click Save Achievement. If it were not already unlocked, you should see a jump in your gamerscore under the profile tab. Go through the rest of your Halo 3 achievements, and do this for ALL the Vidmasters you encounter. SET THE TIMESTAMPS TO DIFFERENT DAYS. (Like, 1st vidmaster earned 7 days ago, 2nd vidmaster earned 6 days ago, and so on...) DO NOT SET FUTURE DATES .

Go back to the Profile Tab, and now select Halo 3: ODST. The timestamps are everything here. Do EXACTLY what we did for Halo 3, and make sure the Vidmasters are unlocked ONLINE with timestamps on different days. Be sure to click Save Achievement[To Profile] everytime you do an individual achievement through the Achievement Tab!!

Step 3: Saving, Rehashing, and Resigning
On the Profile Tab, click Save Profile. Go to the Security Tab and hit Fix. Go back to the Profile Tab and hit Save Profile again. If you REALLY want to be safe, drag it into modio and hit the REHASH/RESIGN button.

Step 4: Overwriting your HDD or Memcard
Go back into Xport 360, Partition 3, Content, Your Profile Folder, FFFE07D1 (Dashboard Data - Gamerpics, Themes, Profile Data, etc), then 00010000. Drag your newly modded profile into xport and overwrite your old one(Click Yes To All when messages display).

Step 5: Updating Xbox Live
This is when we put our storage device back into our 360. Go ahead and do that, then turn it on. Sign into your profile, your new gamerscore/achievements should show up, but don't do anything. Just leave it there for a couple seconds...
Now go customize your Avatar. THIS IS VERY IMPORTANT. Make one small change and hit save avatar. It will take longer than a normal save when saving your Avatar for the first time with modded achiements. If you want you can check on Xbox.com to confirm the gamerscore change, but it should have updated after that.

Step 6: Get Recon
I'm not sure if you have to do this, but you should go play a game of matchmaking on Halo 3. It might also help if you wait a few days before making your Bungie Account. But anyways go get on Bungie.net and sign up with your WLID. Activate and link your Bungie Account with your Gamertag. Use google if you have any problems. Now click on your service tag, and click Get My Recon! or whatever the link says to get Recon.

I do NOT take credit for finding this i take credit for making the tutorial.