Programs you need:
Modio: [ Register or Signin to view external links. ]
USB Xtaf Xplorer: [ Register or Signin to view external links. ]
HxD: [ Register or Signin to view external links. ]

You need to make a 4 letter clan tag for this to work!

Step 1: Configure your usb to your xbox. In order to do this you need a usb over 1 gig. Go to the dashboard, go to system settings,go to memery,click on usb storage device, and then it will ask you to configure now, click that.It will take up to one minute.

Step 2: Extract your profile to your usb. Go to Memery, hard drive, gamer profiles, and click on the one you want to mod. Click move then move it to your usb.

Step 3: First you will need to extract your profile to the desktop.

Step 4 : You can do this with XTAF USB Explorer, if you are using a transfer cable. I assume you will already know how to extract your profile. For USB Xplorer, File Open than click content > E00000 Numbers after this > FFFE07D1 > 0001000 > E00000 Numbers after this (extract this to your desktop).

Step 5: Now its time to open your profile in the hex editor, First open up HxD and click file > open then choose your profile. Now press CTRL-R or press search > replace

Step 6: This window will now popup, type in your clan tag you made in MW2 before you extracted your profile and name it what you are replacing it to. Then click replace all.

Step 7: My clan tag was "HAHA" so in this case, it will then search for all the words "HAHA" then it will replace that with what I want it to be, "F***".

Step 8: Close HxD and open up modio, drag your profile into modio and click rehash and resign.

Step 9: Now go back into USB Xplorer and delete the PROFILE (On the usb, Not the profile folder or the one you just rehashed and resigned) and click inject and select the profile you just rehashed and resigned.

Step 10: Safely remove your usb put it back into your xbox and there you go you now have a modded clan tag. You can tell all your friends about your awesome clan tag!

I like giving credit to those that utmost deserve it.
Thanks B3asTxM0dd3r for your help.