Although there are YouTube videos on how to do the Epley and Semont maneuvers correctly, unfortunately, patients rarely do it correctly when doing it privately at home resulting in prolongation of their symptoms.
You can buy it on Amazon.
Watch a video here on how this device works.
Check out a flowchart on how to diagnose BPPV correctly and employ the correct maneuver to fix here.
Efficacy of a New Home Treatment Device for Benign Paroxysmal Positional Vertigo. Archives of Otolaryngol Head Neck Surg 136(7):682-683, July 2010.