Instructions
Select your SCV units and task them to gather minerals and vespene gas until you have 150 and 100 of each, respectively. Select one SCV unit to build a Factory and task the rest to collect minerals exclusively until you have at least 600. When it finishes building the Factory, task it to collect minerals.
Select the Factory and choose to produce as many Hellion units as you can afford. As you collect more minerals, build more Hellions until you have at least six created and ready to go.
Select all of the Hellion units you've built and move them into Zerg territory. If you have the Orbital Command upgrade built onto the Command Center, use it to sweep the Zerg area, removing the fog of war and revealing burrowed units, including Infestors.
Spread out your Hellions and attack the Infestors. You do not want them close together in case the Infestor uses its fungal growth ability, which immobilizes and damages enemy units. Both the Infestor an Hellion units have 90 hit points, but the Infestor slowly heals unless you completely destroy it.
Attack any infested Terran units that the Infestor spawns during your assault, as these units can attack you while the Infestor can't. Likewise, if the Infestor takes control of one of your Hellions using a neural parasite, it retains control for up to 15 seconds unless you sacrifice and destroy that unit.