It's not as hard as you might think. Loosen all the strut mounting nuts and when you can't turn the back ones any further jack up the front end just enough to let you push down on the front wheel. Push down until the bolt for the strut begins to go down and remove the nut. Place the strut bar mount on the strut tower and reverse the process. You will find that using an open end wrench on the back nuts will be easier than trying to get a socket on there.
When you're done it should look something like this:
I hope that helps. If it's not clear enough let me know and I'll answer more specific questions. My installation took a total of about an hour including adjusting the bar. Good luck and happy modding.
Try this DIY:
http://www.scionlife.com/forums/viewtopic.php?t=29717