This is done by referencing the MMEL from the manufacturer and tailoring it to that operator's aircraft based on the type and number of equipment installed on board.
These procedures will typically involve tagging out and placarding the equipment as inoperative as well as noting aircraft performance reduction as applicable.
MEL deferrals often come with stipulations: they may only be allowed for a set number of flight hours, cycles or calendar days before the fault needs to be corrected.
Per the FAA approved MMEL for the A320 family, the aircraft would be permitted to fly at night with one landing inoperative provided the taxi and takeoff lights work properly.
Typically, NEF deferrals can be signed off by the flight crew to defer interior components without requiring a mechanic to inspect the aircraft - though this will depend on the operator and regulating body.