Hi mate! Cosmin is right about this. This is not a difficult technique since the movements is more natural and if you try doing the sweep just with the right hand, you will notice that you are already able to play it fast. The difficult parts are, the synchronization between both hands and making everything sound clean (no unwanted noises) and clear. I remember that when I was starting with this technique, I practices around 2 hours everyday 2, 3 and 5 strings sweeps slowly and one day, magically I could do it fast. It seems that our mind does a click and suddenly you can play this fast.
One thing that you will note on Muris video and also on most of the players that play Sweep is that we do a circular movement among the strings with the right hand. It's very slight but it's there. Check Malmsteen and Kotzen for more examples. Try to emulate that movement.
My suggestion is to be patient, practice using metronome, concentrate on timing and on making it sound clean and clear. Also, learn many different lessons based on this technique to practice different arpeggios and combinations.
And finally enjoy it! That's all.