mobile

I have an icon stuck in my task bar prompting me to install the Lollipop update as well as regularly showing me full screen prompts when I unlock the screen that I have to keep cancelling. I don't want to upgrade to Lollipop at the moment as the phone is working fine as is and there's a couple of apps I use regularly that don't work with Lollipop so I'm trying to find how to cancel this prompt as it's getting irritating.

I found some advice that suggested disabling notifications on the Google Play Services would work but it hasn't, I've also tried disabling notifications on the app that is generating the alerts but all options for it are greyed out. The phone is a stock N910F that isn't rooted.

Thanks,
John