New: Restore to Froyo DK28
0) Download and install the appropriate drivers for your Windows system:
32-bit drivers
64-bit drivers
Plug your Epic into your computer via USB and let Windows recognize your phone/configure the drivers. After Windows is done with the drivers, unplug your Epic.
1) Download the following:
Froyo DK28 (do not extract this file)
Odin3+v1.61
If you have problems with Odin recognizing or flashing your phone in the following steps, you should first try using a different USB port and/or cable. If you are still having problems, you can try uninstalling the Samsung drivers you downloaded from the link in Step 0, and download and install this driver (select "Software" at the bottom; it should say "Device(Install),USB Driver (Software) (ver.1.0)") instead.
2) Boot your phone into download mode by powering off your phone holding "1" on the keyboard and holding power until you see a yellow sign with an android digging.
3) Extract "Odin3+v1.61andepic.pit.zip" into a folder on your computer, then launch "Odin3+v1.61.exe".
4) Press the "PIT" button and select "victory_8G_100528.pit", then press the "PDA" button and select "SPH-D700-DK28-8Gb-REL.tar.md5". On the left side of the Odin screen, make sure only "Auto Reboot" is checked.
5) Plug in the USB cable (if it's done right you should see a yellow Com device light up in one of the rectangular boxes).
6) Click Start and wait until you get a green box at the top that says success. Your phone should reboot.
Note: DO NOT unplug your phone while Odin is flashing your phone. Unplugging early can cause your Epic to be permanently bricked. If Odin appears frozen/stuck, wait at least 5 minutes before unplugging and trying again (after 5 minutes any process Odin is attempting to complete will have ended).
If you get an error that says "md5 hash is invalid", try starting again from Step 1d and only use "SPH-D700-DK28-8Gb-REL.tar.md5", omitting the "victory_8G_100528.pit" file. You can also try removing the ".md5" from "SPH-D700-DK28-8Gb-REL.tar.md5" and flashing with and without the "victory_8G_100528.pit" file.
Troubleshooting
If you're having problems getting Odin to recognize your phone, try uninstalling the Samsung drivers you downloaded from the link above, and download and install this driver (select "Software" at the bottom; it should say "Device(Install),USB Driver (Software) (ver.1.0)") instead.
If Odin does recognize your phone but is failing during installation of the system files, you may have a bad download. Try downloading the files again.
Some users have had success by not including the .pit file in their installation.
If your phone turns off and does not respond at all, remove and replace the battery to get it working again.