Default porting

hi guys i have been doing some research into my n5100 and im guessing that the firmware is coming to a end withe it being on 4.2.2 in my region.
so i am looking at now playing around with the device ie porting a rom. i have been doing some research for this and got quite hot at it but. i ma looking at porting a rom from the note 2 to our note 8 n5100 as it has the most comparable spec ie ram cpu chip gpu, the olny trouble i am facing is porting the rom that is 720 x 1280 pixels, 5.5 inches to note 8 size at 800 x 1280 pixels, 8.0 inches. i was wondering if any1 could guide me on the step as porting stock 4.3 to out note with note 3 feature would be great.

any help would be appreciated and im sure it would by other note 8 users