Seriously? It only took about 30-45 mins of constant practice to get them for me, but everyone’s differenent.
You can do them different ways.
First way: Land on your pedal, and start swinging the uni back and forth slowly to get momentum. Then on the last swing, make the pedal conect with your foot when cranks are around horzontal. Now just tuck the uni a little and combine with the momentum you got and your up. I think of this way as how Ryan Atkins used to do them, like in this short vid. http://www.unicyclist.com/index.php?page=gallery&g2_itemId=84516 (on the white rail)
Second way: This is how I prefer to do them. Instead of swinging the uni up and then connecting foot to pedal, you are going to land on the ledge (or whatever) and bring the uni up so the cranks are horizontal. Put your foot on the pedal, and lower the uni a few inches, but keep your foot on. Now just bring your foot, leg, and the uni up and tuck.
Hope I helped.