I’ve posted about this before. In fact, I’ve written that sentence before. 
As with all such exercises; start slowly, build up speed slowly concentrating first on sounding the notes perfectly. Use a metronome.
Have fun.
"It takes a lot of devotion and work, or maybe I should say play, because if you love it, that's what it amounts to. I haven't found any shortcuts, and I've been looking for a long time."
-- Chet Atkins
-- Chet Atkins