Assuming you've used the Owner/Tools and entered the new owners name in the box provided, then an E Mail will be sent to the new owner. That E mail has to be opened by the new owner and in doing so has the effect of transferring the ownership over.
There was a problem a long while ago with the issuing and/or receiving WGT Emails concerning this but it was supposedly fixed by WGT.
However if the new owner hasn't received any E Mail from WGT, contact customer services and they will help.
Hope this helps, good luck.
AK