samsung J1 ace SDecember card saga

[Jax_1_]

So after searching hours, days, months for a way to set my 16gig sd card as the default storage on my Samsung J1 ace lollipop 5.1.1. - (sigh) - the only 2 answers I get is to 1: Try upgrade to Marshmallow and 2: is the same question frustratingly posted in the answer...er...place.
So we must move on...
I now would like to know how do I upgrade said device to Marshmallow? Can this even be done ? If not, please, someone smart out there - explain to me why does my device takes a 128gig SD card yet the "window of passage" from 'device storage' to 'big bright open spans of SD storage' is like the proverbial eye of the needle and longed for movie download - the camel?
HELP ME...please

 

[Jax_1_]

MERGED QUESTION
Question from Jax_1_ : "samsung J1 ace SD card saga"

So after searching hours, days, months for a way to set my 16gig sd card as the default storage on my Samsung J1 ace lollipop 5.1.1. - (sigh) - the only 2 answers I get is to 1: Try upgrade to Marshmallow and 2: is the same question frustratingly posted in the answer...er...place.
So we must move on...
I now would like to know how do I upgrade said device to Marshmallow? Can this even be done ? If not, please, someone smart out there - explain to me why does my device takes a 128gig SD card yet the "window of passage" from 'device storage' to 'big bright open spans of SD storage' is like the proverbial eye of the needle and longed for movie download - the camel?
HELP ME...please

 

[Jax_1_]

MERGED QUESTION
Question from Jax_1_ : "samsung j1 ace memory card saga continues..."

So after searching hours, days, months for a way to set my 16gig sd card as the default storage on my Samsung J1 ace lollipop 5.1.1. - (sigh) - the only 2 answers I get is to 1: Try upgrade to Marshmallow and 2: is the same question frustratingly posted in the answer...er...place.
So we must move on...
I now would like to know how do I upgrade said device to Marshmallow? Can this even be done ? If not, please, someone smart out there - explain to me why does my device takes a 128gig SD card yet the "window of passage" from 'device storage' to 'big bright open spans of SD storage' is like the proverbial eye of the needle and longed for movie download - the camel?
HELP ME...please
Jax