1) Turn off the gas and disconnect the power
2) Remove oven door. There requires that you remove the two square drive (SD) bolts on the inside, partially close the door and lift it off the hinges.
3) Remove the grills.
4) At the back remove the rear shield (aluminum panel held by 2 SD sheet metal screws.
5) this exposes the broiler igniter and its two wires. If its been replaced in past, there should be two porcelain screw-on wire connectors. Undo the connectors by turning them counter-clockwise. With a volt-ohmmeter, measure the resistance across the igniter. If its open circuited, its broken. If not, then its in the circuit board, and this help stop here. If this is the original igniter, it ends in a plastic connector. Disconnect by pulling it apart from its mating plug and again, check the continuity of the igniter. If its defective, reconnect the connector and cut each wire on the igniter side. Strip back about 1/2 inch of insulation on each lead.
6) inside the oven, using the SD driver, remove the 4 screw securing the broiler burner from the roof of the oven. The burner can now be removed, pulling the burner away from the gas jet on the right.
7) The igniter is now exposed and can be remove by removing the two SD drive screws.
8) Replace with the new igniter, being careful not to touch the black element, and feeding the wires though the rear oven wall.
9)Reverse the above dissembly procedure.
10) Broil the sausages.