Evdo droping to 1x

[storx]

"Go to EPST, edit, and check under the security settings. For Alltel, the 2nd line down, HDR AN AUTH Password, should read your hex esn, NOT "alltel". Change it to your 8 digit hex esn, reboot, and, at least for me, it made all the difference."

im still new to this site can one of yall please go into more details on how to do these steps??
LIke how do i get to the EPST to edit all this.... Im still on stock rom and looking into upgrading and i wanna know how to do this so when i get done upgrading mine i can change it to fix this issue....