My son and I took the back panel off the dryer and found that the dryer was full of lint. It was very dirty and probably explains why the dryer had no been working as well. We cleaned the dryer out, took off the old air duct assembly and replaced it with the new one. We also replaced the old dryer hose while we had it pulled out. The repair was very easy, simply a matter of unscrewing screws and then reattaching them. Based on how dirty the dryer was it is probably a good idea to check the inside occasionally and clean it out.