Chris,
I see what you mean. It's on that left side of the housing. It does appear there is thermal paste there.
I'm going to be honest with you. We did this in class with non-functional devices, as you could probably tell since we had no hard drive in ours. We did not have access to thermal paste nor was it necessary for us to reapply any since the laptop didn't work from the start. I'm sorry if we provide no guide on how to reapply the thermal paste and I wish you the best of luck in doing it! I am sure there are some other guides on here that include working with thermal paste, if you are not already familiar with it.