Did you bother to do a search for - say - "Zafira key programming" ?
That would have very quickly led you to:
http://www.programyourkeys.com/Program_Car_Keys_-_Vauxhall_Opel.html
https://www.youtube.com/watch?v=QeuOWgU53SQ
http://www.honestjohn.co.uk/forum/post/?t=22313
Anon
April 2016