Identifying bottom bracket
I'd ask Trek.[1]  Most likely you have a 20-tooth splined bottom bracket that the Park Tool BBT-22 would remove[2], but check first.  You'll also need to know what width the bottom bracket is (varies) and its threading (probably ISO).  

You may be able to just replace the bearings and not the whole bracket.  If you want to go that route, you're best off pulling the bottom bracket out and taking the bearings to a bike shop.  Might be easier to just a whole new one, though; the races could be messed up if it is making "knackered-bearings" sounds.  

You will also need a crank puller, like this one.[3]  And a metric ratchet set.

[1] http://www.trekbikes.com/faq/contact.php

[2] http://www.parktool.com/blog/repair-help/bottom-bracket-tool-selection

[3] http://www.parktool.com/product/universal-crank-puller-for-square-taper-and-splined-cranks-cwp-7