How can I extract a .pk3 file?

[Singularity]

Like many people, I'm getting into QIII editing (through Elite Force) to prepare for JKII, and so I downloaded PakScape, but I can't figure out how to make it extract pak01.pk3 (EF's main pak). I'd appreciate it if someone could explain how to operate this program (and I have been checking out the tutorials on Wilhuf's list, but they're pretty spotty).

[UniKorn]

You can open a pakfile with winzip

[Singularity]

Thanks.