Watch the Twister: 1 online guitar lesson by Jim Campilongo from Sonic Tele
I highly recommend using the hybrid picking approach to the double stops as demonstrated on the video as this is an economical way of playing that will eventually lead to a smooth transition from part to part. I also recommend learning these parts in small chunks. Go slowly and don't feel pressure to go to the next part of the song until you have a good feel for the preceding parts. And don't be afraid to play the pull offs & the chicken pickin' lines with some muscle behind it. This will allow the song to really pop at the right times.