you referenced this thread earlier...
[How To] Return to Stock / Fix Bricked Epic - xda-developers
this is word for word from it...
1. Open odin
2. Put your phone in download mode (Shut it off, wait for lights to all go out, then hold 1 on the keyboard while powering up)
3. connect phone (you should see odin put a Com4 or something like that in the first box. The actual number is NOT important what is important is something popped up there when you connected your device, meaning ODIN can see it)
4. Select the pit file on the right in the pit section
5. In the PDA Section you place the full Stock tar (SPH-D700-DG27-8Gb-REL.tar around 255mb) for a full wipe and full return to stock
6. check reboot on the left with DebugEn (only those should be checked)
7. Hit start. It will do its thing. Doesn't take long you can see the progress bar. If it sits on File Analysis for longer than 30 seconds its not going to happen. See the troubleshoot section below.
Device should reboot and should be done.
steps 4 and 5 are key!