How do I stop software update download on Galaxy S6?

[AC Question]

The other day I made the mistake of manually checking for software updates on my Galaxy S6 and ever since there has been a notification telling me to download the latest update. I thought by clicking it I may be able to start the download and then cancel it, but unfortunately it's started the download with no way to stop it (apart from turning off the WiFi).

The download is about halfway through now, although paused as the WiFi is currently turned off. Is there any way to stop this downloading? I understand that as soon as the download is complete the phone will bug me even more to install the update.

I've tried going into the applications manager to disable the software update app, but greyed out. I'm desperate to make the download stop as I don't want to upgrade to Marshmallow as my phone is working fine as it is!

 

[belodion]

After the download, you can boot into Recovery and try a wipe of the Cache Partition if you want to.

The Nexus 5 I'm using right now was good on KitKat. Then I received Lollipop, and it was still good. Then I received Marshmallow, and it's still good. Are you sure you won't be tempted?

 

[Tim1954]

If you turn off your WiFi the device may continue on mobile data costing you heaps of its a big download! (Nougat was 1.2Gig)
Fiddling in middle of update could result in bricking your device, so tread carefully there. In any case, you have committed to update, so you might as well give it a go as Belodion suggested. You can go back if you really really really hate it....