The units you start with will be good defenders for your base throughout this mission. If you lose any in the upcoming battle, replace them as soon as you get to that point in the walkthrough. Group all your combat units and take them north. Destroy the Garm base, and build your own there. Build two hatcheries almost side by side, near the resources. Pump out a total of twelve drones working on minerals, then get your extractor (three drones for that). Keep your forces home during all this to protect your base. One of your target zerg bases is just to the west of yours, so you don't want to be caught by suprise.

You've got your economy running and should now know what to do - build a spawning pool, hydralisk den and evolution chamber. Some creep colonies on the west and eastern side of your base woudln't hurt, either. Get the carapace upgrade (keep picking carapace as you evolve) and start working on upgrading your hydralisks and zerglings while you build some of them, along with zerglings. Get a total of 24 zerglings and eight hydralisks. While they are building, upgrade your hatcheries to lairs and continue purchasing upgrades for your units.

When your new attack group is ready, take them up the ramp to the west. Focus your two groups of zerglings each on different sunken colonies while the hydralisks spit at any units in the enemy base. It won't take long to be destroyed, that way. After you've accomplished this you can move further up the tech tree. Build a queen's nest and spire back at your base. It's up to you to build an expansion base at the location you just cleansed. Just build a hatchery/extractor and reinforce it with some units so the enemy zerg don't build a base there again.

While your lairs are upgrading to Hives, replace any zerglings you lost in the first battle. You can take the reinforced group you first attacked with and head east of the destroyed zerg base, toward the area in the screenshot. You'll encounter another base you can take out without too much trouble. Do just like you did before, letting your zerglings run amok while your hydralisks, controlled by you, focus their fire on enemy units. After the battle's over, leave whatever's left of your forces in that area to guard it from any drones building a new base.

Meanwhile, you should have a hive now! That's great, but it's not all that necessary as you've seen. It would be smart to build about six guardians and six mutalisks since you have all the resources. You should reinforce your first group with hydralisks and zerglings, keeping them in the area of the second base while your guardians and mutalisks are being made. When they're done, you can push for the final zerg base. It's north of where you just attacked, and spreads all the way west across the map. As you proceed further keep sending reinforcements to your troops. Stop and rest in a safe location if you must while they are en route. Focus all your air units on any ultralisks you see, for they are quite powerful and threatening to your ground forces. Another bothersome thing these zerg will use against you are the numerous scourge. Try to attack them with hydralisks to keep your guardians and mutalisks safe. For that reason you may want to up the number of hydralisks in the battle. You certainly have the resources.

This mission should be pretty easy, albeit a bit lengthy. You may have to research the ventral sacs ability for your overlords to transport your units to the two places you can't reach by land. Otherwise, use your guardians to finish those sections off. If you're looking for the last of the zerg, there is a small area on the western side of the map with several of each type of colony. Destroy it to finish the mission. If it's still not over, you might have to look around some - they may have built a new base!