A method for servicing a heater core installed in a heating, ventilation, and air-conditioning (HVAC) assembly for a motor vehicle includes removing a sealing attachment from an interfacing connection interfacing with the heater core. The method includes sliding the heater core in a direction of insertion. The method includes disconnecting, from the heater core, the interfacing connection. The method includes removing the heater core in a direction of extraction, the direction of extraction being orthogonal to the direction of insertion.