how to set up an upfront theme

Hello Sirs,
One of the reasons i wanted WPMU was for its choice of themes.
However, it has been months and I didn't figure out on how to use one. After a couple of trials, now and then, I am almost resigned.

It would help if there was just a simple "how to" guide. At least, on how to adapt one Upfront theme for a homepage of a simple blog.
After that, either one improves making tweaks one-by-one or ask help.

I selected Spirit above just to fill the space. My difficulty is with Piano as well.

[Even while writing this, I wonder if I tried enough. I thought like that and refrained from posting this several times in the past. But no, even setting up WPMU was less confusing]