Download the .zip for the ROM you want and put the .zip on your sdcard (make sure it's named something that you'll recognize). Make sure that it's an EB13 ROM and NOT EXT4, since Epic Experience v2.0.08 is EB13 based and is considered RFS so you are good to go.
Power off the phone.
Do the 3 button death grip (i.e. press and HOLD volume down key, camera key and power button key). When you get into recovery, your volume keys will scroll your cursor up and down and the camera key will select the item highlighted.
MAKE A BACKUP!!!
Once the backup is completed, wipe data (three times), wipe cache (three times) and finally click on advanced and wipe dalvik cache (three times). Go back to the main screen and select "install .zip from SD card" and select the .zip that you put on your SD Card that is the ROM you want to flash.
When the ROM finishes flashing, select Reboot Phone. Wait for the phone to load (can take 5-10 minutes).
Now... you have a choice. You can either reload everything manually OR you can do it the easy way.
If you want to try the easy way (which is what I do when I go from ROM to ROM), power the phone back off and boot into recovery. Select "Backup and Restore" and then "Advanced Restore" and restore DATA only. Then select Reboot Phone.
Enjoy the ROM!!!