Again, two choices, I chose bottom. OK, you've got the mining down. This time, do a set of scouting with the three trikes. This is a favorite pasttime of mine - a group of 3 roaming around looking for singletons to demolish. Build the refinery, barracks, then light factory and kick out trikes. Leave your men behind - split into two groups to guard your base. By the time you find their base (bottom middle), you should have five trikes ready for the attack. Send them all down and take out the base. It should be pretty easy.

Dune 2000 Walkthough Index