As everyone has stated, you won't learn this technique in a few days. If you do, you probably aren't doing it right or it will be sloppy as hell. I've been playing almost 16 years now and even though I am confident at sweep picking there are still patterns that I run across that trip me up.
Get on youtube, there are probably a million lessons on sweeping with some incredibly good players. A few things that really helped me...
-Practice clean (stated before but worth reiterating)
-Avoid "box" patterns/arpeggios. A lot of sites will show you something like an A Minor Arpeggio like this
-------------5-8-
-----------5------5
---------5----------5
-------7--------------7
-----7------------------7
-5-8---------------------8-5
So you end up barring or rolling your finger on the stacked 7's and 5's. I think these types of shapes are the hardest to play cleanly and make it even more difficult to learn the technique.
-Also, for the shape above....start with an upstroke on your E string, then down stroke for the sweep.
Hope this helps. Best of luck!