Opt out of Marshmallow update on Samsung S6 Edge with AT&T?

[kilometerss]

Hi,
Does anybody know how to opt out of this update? Google's killing the unlock screen by app feature is utterly painful to my lifestyle and use of my phone. I cannot lose this feature. If anybody knows how to opt out of the update, or enable this feature on marshmallow, it would be greatly appreciated. Thank you

 

[kilometerss]

Wrong update - it was a standard update by Samsung. I'm still seeing a significantly lower performance since it updated, however, which sucks... coincidentally after a new model phone is released. Hmm..
Anyways, if you're reading this, sorry no answers could be given if you have the same question