Great instructional DVD from the guru of slap bass.
Please note this is intended for upright, double, contra, doghouse bass. Not that electric players could not learn something from this but it is not electric slap technique.
I also think Lee uses a flat tuning in this video.

ScreenShots:

Download:

FILESONIC.COM
http://www.filesonic.com/file/4168679104/Rockabilly_Slap_Bass__Lee_Rocker.part1.rar
http://www.filesonic.com/file/4168680054/Rockabilly_Slap_Bass__Lee_Rocker.part2.rar
http://www.filesonic.com/file/4168680164/Rockabilly_Slap_Bass__Lee_Rocker.part3.rar
http://www.filesonic.com/file/4168680264/Rockabilly_Slap_Bass__Lee_Rocker.part4.rar
http://www.filesonic.com/file/4168680314/Rockabilly_Slap_Bass__Lee_Rocker.part5.rar

FILEJUNGLE.COM
http://www.filejungle.com/f/EEQQBu/Rockabilly_Slap_Bass__Lee_Rocker.part1.rar
http://www.filejungle.com/f/5qnJ46/Rockabilly_Slap_Bass__Lee_Rocker.part2.rar
http://www.filejungle.com/f/32f8Tr/Rockabilly_Slap_Bass__Lee_Rocker.part3.rar
http://www.filejungle.com/f/kNbXtw/Rockabilly_Slap_Bass__Lee_Rocker.part4.rar
http://www.filejungle.com/f/KaqtvU/Rockabilly_Slap_Bass__Lee_Rocker.part5.rar

UPLOADED.TO
http://ul.to/hyihjb6y/Rockabilly_Slap_Bass__Lee_Rocker.part5.rar
http://ul.to/kn718htg/Rockabilly_Slap_Bass__Lee_Rocker.part4.rar
http://ul.to/qjcylgzp/Rockabilly_Slap_Bass__Lee_Rocker.part3.rar
http://ul.to/1s0tleek/Rockabilly_Slap_Bass__Lee_Rocker.part1.rar
http://ul.to/8eo32kmt/Rockabilly_Slap_Bass__Lee_Rocker.part2.rar