Ryobi Circular Saw

So after dropping off the wife to the high street with my daughters so they can go shopping, the old man (me) gets to go and play with the dirt. Actually the plan was to go and cut the joist up into bed lengths of 2.4m and 1.2m with my new toy. Thing is I could not work out how to lock the cardboard blade so that I could undo the locking screw to put the new blade in. I really should have read the manual or left it in the tool bag!

So I spent the few hours painting the timber joists I had already cut to size.

Got home took the saw out of the bag and immediately spotted the button that locks the drive shaft so you can unscrew the locking bolt. Now why didn't I and Wally find that on site when we were looking for it ?