The procedure for the replacement of dryer heat element depends on the model of the dryer. Generally, the replacement of a dryer heat element involves dismantling the dryer to remove the old heat element from the dryer's chimney and inserting a new element before reassembling the dryer.
First, unplug the power supply, and pull it away from the wall to access the vent hose usually located at the back of the dryer. Loosen and remove the rear access panel. Detach the wires connected to the limit thermostat, and remove the terminal wires at the bottom of the chimney. Loosen off the screws under the lint filter, and remove the filter.
Open the dryer top by sliding a putty knife between the cabinet and the top to release the clips that secure the top onto the cabinet. Lift the top and support it with your head, then remove the strap. Pull the chimney top from the drum bulkhead, and detach the chimney from the mounting brackets, taking note of how it sits on the brackets. Unscrew the sheet metal, and remove the old heat element. Insert the replacement heater element in the place of the old one, and reassemble the machine. Lastly, plug in the dryer, and test it.