How can I downgrad my Samsung J5 (SM-J500FN) from 6.0.1 Android to 5.1.1 Android?

[AC Question]

Hi
A few weeks ago, my phone upgraded to Android Marshmallow. Now I want to get rid of it and go back to Android Lollipop.

It's because I can't use my SD card anymore. While I found several descriptions how to use it as intern storage, I tried to do this. But it didn't work with my model. I read that many users of this device have the same problem.

I use my phone with lots of apps and I don't want the SD Card to be useless (well, music and pics are going there, but I don't need 16GB for that!)

I am not really good with technics, so I have absolutely no chance to do it by myself without tipps. I looked for tutorials, but most of them are for the J500H. I am unsure if they will work with my phone and I really don't want to destroy it.
One video said I should look up my model at Sammobile - I found it there, but not with my country and carrier. (Germany, Vodafone) So again I didn't know if I could use it for my phone.

Any help is more than welcome!

 

[nahoku]

I'm going to point you to the XDA forum for your model phone. It would be good to also ask your question there in case you don't get any replies here.

Samsung Galaxy J5 Questions & Answers

However, there is this thread from XDA that says you can't downgrade if your phone upgraded to MM. Please read through it as I'm not sure if it applies to your phone or current OS updates.

***Warning*** DO NOT FLASH/INSTALL NEW MARS… | Samsung Galaxy J5

 

[Rukbat]

With an SD card formatted as internal, you no longer have "internal" and "external" storage, you have "storage". The card is still there, but the phone decides what goes where.

If you format the card as external (back it up - you'll lose everything on it), you'll get it back - but most apps won't run from it (it's for file storage, not apps).