This is broken

A great idea from Seth Godin - www.thisisbroken.com a site and video about the inane things people do to wreck a product or an instruction.
He demonstrates that while we worry about internal communication theory we often forget about the simple things. 
Like this Stanley knife that I have just wasted 30 minutes trying to change the blade on. For years these knives opened up and you change the blade risking skin nicks and blood-letting. 
Now they have changed the design and no matter how hard you try the knife will not open.
By trawling the net I eventually found the answer; it actually is an improvement and is probably safer - but nowhere on the knife does it explain how you do it!
The problem is that Stanley's designers have ignored the fact that we men have 20 years' of inate experience of putting in blades the hard way.  Our brains tell us to hacksaw the damn thing open if the button does not work; it does not occur to us to think laterally.
So if you are going to improve things remember to start your communications at the point where your audience are and then lead them to the new way  - no matter how cleverer it is.
(By the way - you press the yellow button and pull the blade out of the front...)