[Kodibuntu 14] How to upgrade from 14 Helix to 15 Isengard?

Hello to all,
because I found some problems upgrading the Kodi 14.00 to the last 17.00 (no video on Intel HD Graphics 4000) I would like to try to update step-by-step: from 14 to 15; from 15 to 16 and from 16 to 17.
So the question is: Is there a way to upgrade the Kodi 14 to 15? (and after that to the other versions?)
I have (re)installed the kodibuntu O.S. 14.04 lts
Really many thanks.
Ciao!