Open the Phone app
Tap Recents, Contacts, or Favorites
Find the blocked number
Tap the info icon or contact name
Tap Unblock this Caller
Open Settings
Tap Phone
Tap Blocked Contacts
Swipe left on the number
Tap Unblock
Open the Messages app
Open the conversation with the blocked number
Tap the contact name or number at the top
Tap Info
Tap Unblock this Caller
Open Settings
Tap Messages
Tap Blocked Contacts
Remove the number from the blocked list
Open Settings
Tap FaceTime
Tap Blocked Contacts
Remove the number from the blocked list