To return back to his form of yore, Rafa needs to make slight adjustments and corrections to his current game. His game of 2010 might be a good one to revert to as well, but that might not be possible; people don't have Time Machine-esque features. In my opinion, here are some things that worked for him in the past:
1. The lefty kick serve out wide, especially on the ad-side.
2. Pinpoint precision ground strokes that jumped after hitting the lines
3. Deep balls, especially down the line
4. Impenetrable service games - in 2010, he held the ATP Tour record for being broken the fewest times
Something he needs to add to his game is the ability to take the ball early and from inside the court. Djokovic has been beating him by stepping into the court and taking the ball early. The long grinding matches he is playing aren't really doing him any favors.
The next two weeks will dictate the rest of his year. Vamos RAFA!!