This is not a difficult song as far as Rush goes. I suggest that you first learn the fills (I think there are maybe 4 of them) such as the ones at the middle and the end of the guitar solo and the 2 that start each of the "subdivisions" sections. Other than those there's not a lot to it, especially if you're not playing over the keyboard parts. Even those fills aren't especially fast, you just need the patience to learn how they go. Listen to the songs until you can sing the parts in your head. Once you can do that, you'll likely be all set to play them properly.