clothes not completely drying

Remove the two screws on the lower front panel. It is easier if you remove the three screws for the venting.I couldn't beleive the amount of lint trapped in there a fire hazard.The heater core is on the lower left corner in the back of the dryer.Remove the two screws and pull the old heater core out.The wires are long enough to pull all the way out.Attach wires from the old one one at a time so you don't mix one up. Then reinstall reversing the above procedure.