You don't have to take the whole thing off....just the nut on the strut rod. Look at the picture above. The assembly is supported but the 3 bolts that come through from underneath and are secured through frame. The nut that is actually on the strut rod is for the travel of the rod itself, not the entire assembly. As long as your car is on the ground like normal and you have weight on the struts, there is pressure pushing the rod upwards. You should be able to see that below the top nut, you will see some exposed strut rod. Thats normal b/c the strut has weight. If it didn't, the nut would be holding all the pressure in the rod and would fall through (up) once the bolt is released. Honestly, I just did this the other day w/o any problems.
Another thing. I didn't have to put any additional washers onto my Tokico's to elimate the sound. At first I didn't put the big washer on, and had to go back and fix it. But as far as putting additional washers on it, not for me. I also had an impact wrench to help me out, so maybe that helped me. But what you need to watch for is if you are spinning the strut rod when tighting/taking off the rod bolt on top.
-z