hub assembly bolts

I am changing my wheel hub bearing assemblies on my 1999 Oldsmobile alero this weekend. My manual shows that there are torx bolts securing the hub assembly to the steering knuckle. Does anyone know what size these torx bolts are? I wanted to try and get the right size torx socket before starting this job. Thanks for the help.

I'd eye-ball them before I bought anything. See:
http://www.automotiveforums.com/vbulletin/showthread.php?t=762786&highlight=hub+assembly

I did my front hub assemblies, they were held on by three 13mm hex-head bolts.
Hope this helps.