how does one bend a note while playing harmonica ?

Answer 1

This is a very effective way to add variety to your playing but you have to practice until you really get it. It's hard to describe how to do it, on a draw note try sucking in your cheeks as you hold the note. The note will change (lower) as you hold the draw.
There are many harmonica sites and yahoo groups that can help as well.

Answer 2

by leaning forward