I posted this verbatim in another thread but applies here. Chord/notes are different but the concept applies. In short, just go slow. Don't worry about playing the song up to speed. Just get comfortable with the changes and speed up from there. From my post:

Originally Posted by: JeffS65

My suggestion is to just go as slowly as you can, without playing along with something and drill going from one chord to another: E to Am, then Am to E and so on. Go slow. Don't worry about speed. As a matter of fact, you will always use this 'start slow' way of learning something even if you're experienced and been playing for decades. Patience is the best friend of a guitar player. Well, after a while you want every guitar on the planet so, so the true best friend is money (hehe) but a close second is patience. Just go back and forth and get used to the movement.

[br]There isn't per se 'muscle memory' in as much as your brain is making a pathway for that skill. If you're trying to go faster than your brain can process, your brain just shrugs and goes 'oh well, whatever...'. Also recall that right now, you might also be trying to strum a melody/pattern in a lesson. In addition to just getting your fingers to hit the right string, you're probably trying to strum a pattern and the same place in your brain has no sense of what is the priority motor skill to focus on. So, start by doing the slow E>Am>Am>E pattern but just one strum per chord change. Once you start feeling like the chord changes are getting a little more natural, then strum a bit. Don't force your head in to competing motor skills.

[br]I mean seriously, I was noodling around with Pat Benatar-Heartbreaker (with some aid of the GT lesson...I mean hey....that solo is awesome!) and for whatever reason, the opening song riff was not clicking. I've been playing a long time but there's always that one thing. The riff is a barred F to a barred G#. Walk in the park. Except my brain totally knew the G# is the 4th fret but my hand kept on going to the standard barred G/3rd fret. Been a long time player so I can tackled hard stuff but this little, dumb interval of F to G# wasn't making it to my hand.

[br]Answer? Go slow.