I made the mistake of letting one of my automotive classmates change my oil. The oil level on my car seems about a half a quart above the high-level mark on the dip stick. What should I do? Drain it a little from the drain plug, or should I just continue driving it? I already drove about 100 miles on it, and it sounds fine. In fact, it sounds a little smoother when I first start the engine. I haven't seen any smoke yet, but then again, I haven't been checking.
TIA
TIA