You will need a subscription to the CrossFit Journal ($25)  to access the videos:

Running Drills With Brian MacKenzie Part 1
http://journal.crossfit.com/2011/06/bmackrun1.tpl

Running Drills with Brian MacKenzie Part 2
http://journal.crossfit.com/2011/06/bmackrun2.tpl

Running Drills with Brian MacKenzie Part 3
http://journal.crossfit.com/2011/07/bmackrun3.tpl

Running Drills with Brian MacKenzie Part 4
http://journal.crossfit.com/2011/07/bmackrun4.tpl

Running Drills with Brian MacKenzie Part 5
http://journal.crossfit.com/2011/07/bmackrun5.tpl

Running Drills with Brian MacKenzie Part 6
http://journal.crossfit.com/2011/07/bmackrun6.tpl