Hi @Darryl
You’re doing great!
Oh, and welcome to the club - everybody struggles with this exercise! @soren_ladegaard Soren refers to this post, probably.
Personally, I was able to play the riff, but the full song… oh dear, my poor left hand. And getting the muting/staccato decent, or the whole discussion which version is “the one.” 
Bookmark the exercise, it’s going to be a great way to check your progress. 