Installing lineageOS I have a tab S2 stuck on 5.02 I wanted to upgrade the software to lineagOS  There are lots of information out there but nothing that can help me. A few things first that I need to share. Im usung a MAC I once unlocked my device and knox is now void so must be unlocked. the bootloader I cant tell if unlocked. using an app I tried to check but came back with an error of " Sorry! root access is not properly installed on this device"
The tablet is in developer mode, there is no OEM mode or anything like that, usb debugging is turned on. 
I have tried several things using terminal but didnt work with home brew an adb services. these installed on my mac but got as far as trying to add fastboot devices but denied on the terminal, but that probably makese sense if the bootloader is locked. 

MOst insgtructions imply that you know what to do and dont exxplain much. Can anyone please assist with step by step instructions so I can complete the process of installing LineageOS. 

Id appreciate your time if you can help me.

KInd regards
Samsung devices does not have fastboot mode, at least i am not aware of Samsung devices with Mediatek chipset  

the bootloader lock status can be checked only from download mode screen  

step by step instructions vary on device and android version. your android version 5.02 may not have OEM unlocking in developer options, you can skip this step  

on the other hand be aware Samsung does improve security continuously and may roll-out new features even to old devices, which leads in non-working tutorials  

also rooting apps like Magisk do silently change usage at will which may end up in data loss if tutorial isn't up to date