It works fine without cellular. In the hands of someone who can install Linux, it shouldn’t take more than an hour (if you have a not-dialup internet connection).

First, apt install adb heimdall-flash. These are the basic tools for interacting with Samsung phones and Android devices in general from a Linux machine.

From there, follow the instructions I linked below, which basically amounts to getting root and unlocking the boot loader using Heimdall, then flashing TWRP, which is a recovery program, then flashing LineageOS from within TWRP. It’s not hard, but be sure to follow the right set of instructions, because the files for the Verizon, AT&T, and Sprint phones are not compatible.

Assuming you have the Verizon model: https://wiki.lineageos.org/devices/jfltevzw/install