How to Install.
Flexible Squares
1. Go to customize and change your style to S2. Save changes.
2. Under Select A New Theme, choose Flexible Squares.
3. Click on customize your theme.
4. Next click on Custom CSS.
5. In the first two drop boxes, select No. In the third, select Yes (Q: Use external stylesheets). Copy/paste the CSS.
6. Click Save Changes.
And you're done! :D
NOTICE - Please take a look at the FAQs or these very helpful communities: s2flexisquares and everything_lj. If you still have questions, ASK THEM ON THE FAQ POST.