You can change the struts yourself but normally it requires special tools. Search on here for Patrick Wong's thread on how to change the struts on a Gen II. This actually needs to be in the Gen II section if your avatar is correct and you have a 2006 Gen II.
I have not done this on a Prius but generally you'll need a spring compressor and know how to use it. Good news is it's a free rental (with $$ deposit) from most auto parts stores and how-to vids are on youtube and numerous websites. An impact wrench really helps speed things up but not completely necessary. Good jack stands, necessary wrenches/sockets, and floor jack. Penetrating oil the night before is highly recommended on any rusty or dirty hardware.
On one of my Prius I put Sachs in front today. Put KYB in rear 40k ago. And another Prius I put KYB all the way around. Gonna compare soon... Anybody here done a head to head KYB v Sachs or have info about Sachs?
You don't need a spring compressor, if you buy the struts fully loaded. IT costs more, but you get new springs too. And, it is easier to change out.
Peter: If you are not buying KYB Excel-G then you are buying inferior product. In my head to head comparison of KYB Excel G vs Sachs I found KYB Excel G outperforms Sachs suspension. I have tested them head to head in two 3rd gen prius' Both have the same size tires, and alignment done after strut installation. I also installed shocks. KYB in one car, sachs in the other. I put new sway arm bushings and links in both. I have driven them both for a couple hundred miles minimum, at speeds up to 109mph. KYB is the clear winner in precise suspension. I am qualified to compare as suspension is of paramount importance as a racer. And I am a mechanic, ASE certified, not the shadetree kind. Up to you, buy what you want. Get Monroe, see if I care, but if you want the highest quality, KYB Excel G is the best I have found.
I've put KYB Excel g into two more Priuses in the past week. Hands down these are the best. Get the sway bar bushings and sway bar links and shock socks for the fronts as well. Just buy the whole kit. 521 after tax with shipping. I got the install process nailed down to about 2 hours now And the last one I just did didn't need an alignment when I was done. FYI the little yellow dot on top of the Torrington bearing has to face the engine on each side when you line up the top of the strut into the body of the car. This should occur naturally if you've lined up the spring correctly. I have learned to always clean and regrease the torrington bearing. I also put a thin layer of grease on the shock pistons
