Step 1: open Cydia and tap the Manage tab at the bottom of the screen.
Step 2: tap Sources.
Step 3: tap Edit in the upper right-hand corner of the Sources page and then tap the Add button in the upper left-hand corner.
Step 4: Type in UltraSn0w’s repo address: http://repo666.ultrasn0w.com and tap Add Source.
Step 5: Assuming the repo is up and operational, you should see a black screen showing the source being added and packages being downloaded. If you get a “cannot find” error message, then UltraSn0w is probably down.