For the manual, you shift your weight toward your back foot (slowly at first), while you lean a little forward (also slowly at first). Make sure you do NOT lean backward. Instead, lean the upper part of your body (your shoulders and head) toward the nose of your skateboard, while you shift your weight to the back foot. Take a look at the photo to see what I mean.
This is pretty tricky stuff, and you will probably feel like you are loosing your balance. It's perfectly OK to hold your arms out and use them to catch your balance. Everyone does it - even pros!
