Ok, so you're still sane up to this point hopefully.

The next step is to reconnect the flex cable for the digitizer to the motherboard.

This is assuming that you didn't go all Bruce Banner on it in the first place and it is still functioning as prescribed.

Simply slide the flex cable into the connector gently until it stops. It will "bottom out" and you will know that it is where it needs to go.

Finally, use a spudger or your fingertip to close the little lever that we flipped up earlier.

Remember, there was a small piece of tape that was covering both of the flex cables. Don't forget to put that back down. It seems to be there as a kind of strain relief and might actually be valuable.