Go to YouTube and click on settings (one of the buttons on the bottom right corner), then click on playback speed, then click on 0.75. That will slow the song down from stupid fast to just fast. Keep playing along until it becomes easy, then put the speed back to normal.
How long will it take? That's up to you.
There were more than 10 takes when recording this and the story goes they sped it up after the track was laid down. Apparently even Norman Watt-Roy had trouble playing it after that.