There is no differences between installing /e/ or another custom ROM.
This HOWTO will be useful :
You just need to know your device codename (beyond2lte or beyond2qlte or beyondxq) and find a compatible LineageOS for instance.
Download the official Samsung firmware in Sammobile.com/firmwares before. You only need one dumb account and it will take 1h30 to download but you will need it one day to restore your phone.