If you want to change the ribbon try here:
But the locking mechanism (FPC tab) on the board I don't believe you can change out
just go fresh and keep steady, number 3 was a pain for me too
Includes front panel, ear piece speaker and home button. — 43 available at 49.95 each.
You CAN replace the connector on the board, it isnt impossible. It isnt related to the digitizer though, this is for the ear speaker and proximity sensor. the ribbon replacement isnt going to be detailed in that link. If you want to replace the ribbon, look here:
There is no detailed guide to replace the #3 connector because the tools required are quite specialized. You asked about #7 as well? The title of the question and the content is a bit confusing.