You just walk over the edge. But there mustn't be a block one step below it. If there is, you just jump down to that one, if there isn't, then you walk off and grab the edge. Then you can sidle around the edges to get where you need to go.
As bond007106 said, just walk off of the edge as long as there is nothing immediately below you. If there are blocks one step below you which prevent hanging, you can still hang as long as you pull a block right up to the edge (knocking yourself off and hanging from the edge).
It won't be exciting unless we're betting. Besides, like hell I'm going to be exercising with no incentive or reward in sight. - Yukari Tanizaki