Product review (5 stars): Very pleased
My husband and I were able to fix our horrendously squeaky dryer in a little less than 1.5 hours for only $16 (inc. shipping)!  We are novice DIY'ers so if you're more advanced it will probably take much less time.  We were also being careful not to wake a napping baby, so that probably affected our time to complete the installation.  We didn't use the enclosed instructions, but a blog we found online with step by step pictures.  You really need 2 people to put the ball bearing in (one inside the dryer and one behind the dryer), and also to put the drum back in (one to hold the drum in place and one to put the screws in).