I still have the android 5.0.2 on my phone. Every time I check the update it's said there is no update available.
I had the same problem. Every time it would say that there was no update available. The thing is that I think it was because I bought my Edge from AT&T to use it on Cricket Wireless, so that could be why, but anyways I recommend you to go to Best Buy where most Samsung Experience Stores are, they should update it for you with no cost, just backup your files and you're good to go.
Anyhow I would also like to update my phone by myself, does anyone know what the problem is and how to fix it?