Transferring 360 to new PC

Just bought my mother-in-law a new PC to replace her 10-year old unit that's still using XP. She currently has Norton 360 with 3 months left on the subscription. A couple of questions:

  1. How do I transfer her current subscription to the new PC?
  2. How do I disable the Auto-renew for her subscription (I want to transition her to Norton Security)?

Be aware of the following:

  • I doubt that she has a Norton Account. If she did, then it's doubtful that she knows how to access it.
  • We intend to permanently retire the old PC once we've transferred files, so we do not plan on getting another license.
  • I would prefer to have the transfer complete before delivering her new PC, but can work around that if that's not possible w/o the account info or buying another license.

Thanks in advance for any help.