The transactions output are to P2SH or P2WSH address where unlock script allows Alice to spend anytime, but Bob to spend in N days after broadcast time.
I am not much into coding or technical things, how a regular user can perform this task?
Alice (owner) will just set an option of N days in a wallet. Then the wallet creates transactions automatically when sees new UTXO under control. Then it will send it to heir via some standard peer to peer channel (email, messenger, etc.) From Bob's (heir) side a wallet will get and store the tx.
It can be new wallet software with this functionality or an add-on to existing one.