Doing the gamerscore mod can get you flagged as a cheater and get your gamerscore reset ONLY IF you don't abide by the "don't take more than you need" moral.To prevent being banned, do the following:

Don't overuse the program and be sure to reorder your achievements to make it look more legit. Its always nice to have some online achievements BEFORE you mod them, showing Microsoft that you do play legit.

If you want me to, i can do this for you, i can also mod gamerscore for other games for you if you want 8) If you don't trust me, i will do it via Teamviewer. I will always do it for free but Rep and Paypal/MS point donations are always accepted

WinRar- [ Register or Signin to view external links. ] (Needed to open all the programs listed)
Modio- [ Register or Signin to view external links. ]
Profile Editor v2 or higher- [ Register or Signin to view external links. ] extraction password is:calimodz
Hash Block Calculator- [ Register or Signin to view external links. ]

1.Move profile from hard drive to the USB.*skip steps 1 and 2 if you are using a Transfer Cable*
2.Take the USB, put it into the computer.
3.Open up Modio, Click on the big "M" in the top lefthand corner of the screen.*Read from here down if you have a transfer cable*
4.Scroll down to "explore my device"
5.Click "File"then "open/close device"
6.Open the "Content" folder
7.Open your profile's folder(should have your gamertag as the title)
8.Open "profile storage" folder
9.Open "profiles"
10.There will be a file titled with a E then numbers and letters (Example: E00001F3456E890)
11.Drag that file to your desktop(leave modio and your device open) Minimize Modio
12.Open up "profile editor"
13.Click "open" and choose the file you put on your desktop via modio.
14.It will show all the games you have played and the achievements you have gotten for them. To get the armor, you must have played: Halo 3, Halo 3:ODST, Halo Wars, and Halo Reach.
15.To edit achievements, choose the game you want, and click "unlock all(offline)" a message will pop up, just click "ok"
16.After you unlock all the achievements for all the Halo games (or more), go back to "file" then save.
17.Open up "Hash Block Calculator"
18.Go to "file" and open your profile (it should be a big list of #s a and letters)
19.Go to "tools" and "calculate hash blocks"
20.After it says "done", maximize Modio back
21.Drag and drop your profile bach into your USB or HDD
22.Put your USB or HDD back into your Xbox
23.Unplug your Ethernet cable or wireless adapter
24.Sign into your profile (offline)
25.Plug in your adapter or ethernet cable
26.Sign into Xbox Live
27.Look at your achievements, make sure they all loaded, stay logged in for at least 10 mins letting your achievements load.
YOU ARE NOW DONE, CONGRATULATIONS!! Here is an extended tutorial on what to do after you mod your gamerscore due to request
28.Open Halo Waypoint and let it load up
29.Click on "career"
30.Click on "scan achievements" and there ya go

If anyone has any request on how to mod Halo Reach offline, or if they want to learn some of the other mods i know how to do, Just p.m. me and ask me what you want to know, and ill let you know if i can help you or not, im always open to new request