Without a garage this is going to be hard to do. Expect to have the car off the road for about a month. That's realistic. Others may say it can be done in a long weekend, but this is somewhat unrealistic because of all the little things that pop up....broken bolts, electrical problems and so on and so on....
Do you have the tools and ability to perform such a project? Whatever you do, get the JTR manual first and read it several times, cover to cover before you even think of starting to procure parts.
A word from the wise (well, from me anyway)
Read this if you haven't already: http://www.hybridz.org/phpBB2/viewtopic.php?t=19186
Tim