one of the main failings of the MIT guide (which I assume you've read) is it's lack of time spent on tension and appropriate placement of the wrench.
you need to apply tension to the plug (the bit where the key goes) in order to set the pins.
www.howstuffworks.com had some nice interactive diagrams of people picking a standard pin tumbler lock - have a look there and see if you can't figure it out.
bear in mind that you only need the amount of pressure that you'd normaly apply to a key in the lock - sometimes even less than that.