Some relatively long-winded videos, but you can probably pick up a few tips here and there.
Just practice your scales in a way similar to the way you practice alternate picking, except pick less of the notes. The only difference is you have to pay a little more attention to the evenness of the notes, slop/extra noise and of course making sure all the notes sound. You could be sadistic and not pick anything but the first note of ascending strings, but I personally just pick however notes feels natural, whether it is 1 or 0 or 2 if its a slide or 3 if its an extended pattern once every beat or 3 notes or whatever.
Hammer ons are really easy. Pull offs are little harder particularly in the upper registers. The real difficulty comes with combining the two in a phrase or even on the same string, as after you play more than 3 notes on a single string the sound will no doubt lose all it's original force. What makes this silly is that it is even harder to practice it really slow, as then the notes will die out even faster. It's just a thing you have to work on, not really any magical advice to really help out here, other than to make sure you fingers hit/pull off the strings with lots of force BUT NOT pressing stupidly hard on the strings. If you do that you'll tire your hand out instantly and worse yet, you'll bend the string sharp, which is something you really want to avoid.
Practicing without piles of compression/ridiculous amounts of gain beyond a sane man's preference as well as having slighter tighter strings can also help in aiding you practice, even though this all makes legato much harder, it'll make your left hand rock solid compared to if you didn't. Also practice trills like crazy. You can never go wrong with trills. Reworking any old melody line so that it uses more legato works well too, and is a lot harder than you may think.
And I personally find Paul Gilbert vids a lot more helpful than Satch vids that I've found, which I haven't found anything useful in them (apart from that chord warm up excersize that is more or less an easier version of John Petrucci's crazy warm up stretching thing). Not gonna link any right now but they're pretty easy to find. Even if you think of him first for alternate picking he really does tons of legato, and string skipping legato stuff, and its all tons of fun to try out.