Can anyone please show me in a tutorial?
Experiment. Select Edges. When I was working in tech support we would always get questions like this, especially with drawings, and then we would do a gotomeeting and then play around with different features on their screen until we fixed the problem. Create a part, go to snap hook in insert>fastening feature, select different edges into the selection boxes and see what happens. Change the various dimensions and see what happens. You'd probably spend about 2 minutes before you figured it out.
Thanks, ill give it a go :)