The RTFM, or RTFB as [MENTION=197614]fietsbob[/MENTION] is suggesting is not a bad idea. If you have not worked with BB's before there are some things about how you remove and adjust them that are hard to describe. Depending on the tools you already have and your ability to improvise, you might easily spend more on tools than the BB itself.

Looseness could be the crankarms themselves and not bearings. Have you checked that?