Not sure if you've already figured it out, but there are two ways you can pull off your hoods:

1. Peel the hood backwards over the lever. This requires strong fingers and determination. You can make it a little easier on yourself by spraying in a little sloapy water to help ease it off (just remember to wipe it all off when you're done). This might sometimes cause the hoods to stretch, however every time I do it this way the stretch is minuscule if you even notice it at all. If you don't plan on recycling the hoods, this might be the easiest way to go about it.

2. Unwrap your bar tape just passed the hoods. If you peel your hoods halfway over the lever (as much as you can before it gets hard), you will see an allen key bolt. Loosen that completely to take off your integrated shifter. You can now pull the hood away from the lever.

To put new hoods on, you just do one of the two steps in reverse. Soapy water does help, just remember to wipe when you're done.