Very very slowly at first. It's best to turn the tempo way down to like 140 in guitar pro, mute the lead guitar track and play along with it. If you speed the tempo up to quick you will regret it.
To do the sweeps, I'm not sure if you have practiced sweeping before so I'll give you some basic info.
Don't pick each individual string. You glide your pick across them. You might be better off to just glide your pick across the strings without even fretting any notes at first to get an idea of the feel of it. Sweep picking is a catch 22 type deal. It's easier to do faster, but you have to practice it very slow to be able to do it to begin with. Make sure you hit every note on time. When I first started learning it I was playing the first parts of the sweep slower than they where suppose to be, then on the hammer-ons and pulloffs I would play twice as fast to make up for the slowness at the beginning. You definatly don't want to do that. Keep everything perfectly in time. Break it off into sections too. Don't try to learn it all at once. Just a little bit at a time. It probably took me a total of 16 hours of practicing it before I could do it somewhat decent. It takes a while 
Good luck!
(*not sure of the words I use... 
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