Bounce; now that you've got your V5 you will first;
need to set up your own personal Lexus Link Account, with your own password and personal details. visit : Lexus Link | Lexus UK
Once you have the account set up, you go to the car multimedia and link the car with your Lexus account. Better to do this when you're parked in front of your house in order that you can use your home WiFi.
Also depending on the type of phone you have (Andriod or Apple) you go to the Google Play store or App Store to download the phone app for your phone, thus you can use connected services from your phone
If in doubt read the guide from this link: Lexus Link | Lexus UK