So in order to downgrade your iPhone back to iOS 6.1.3, simply follow these easy steps.
STEP 1: Download iOS 6.1.3 for iPhone/iPad and iPod Touch.
STEP 2: Now simply connect your iPhone running on iOS 7 to your computer
STEP 3: Now, open iTunes and select your device, from there press option+click (Shift+click Windows users) on the restore button.
STEP 4: Browse your firmware for your iPhone that you’ve downloaded in STEP 1.
STEP 5: Wait until your iPhone finishes restoring back to iOS 6.1.3…
NOTE: keep in mind that you may only downgrade to the latest publicly available firmware for iOS on an A5 device, even if you have SHSH blobs saved. For older devices like the iPhone 4, you may be able to downgrade to lesser firmware if you happen to have your SHSH blobs saved.
If there is any problem you’ve faced during the downgrading process, please feel free to inform us in our comment section below….