The first thing to do is to download and install iLivestock on the new device and login. Put in your online service code when asked (six letters).
On the new device goto 'Admin' -> 'iLivestock Online' -> 'Data Sharing' and press 'Refresh Database'. This will download the latest master.
Finally, if you want the new device to be the master, login at https://www.ilivestock.co.uk/login, select your services code and then set the new device to be master.
TIP: Name the new device for easy reference while you are logged on!