I agree with an above poster.
If the part you want to play is fast....say 200 BPM.
Try playing the part exactly the same way, but at 50 BPM.
It should be just as difficult at the slower speed as the faster, but it helps to imprint on your brain the right notes and technique.
After playing at the slow tempo for about five minutes, increase by 10 -20 BPM. Repeat until you are up to speeds where smaller increases are necessary.
I wouldn't expect to get up to top speed on your first few sessions, but once you do, it'll be like riding a bike with that part.
