Yes be careful, they are bolts iirc (apparently not according to huitt but it's been a while) and one of mine snapped which needed to be extracted so use caution. Remove the tire, liner and I think you'll be ok. Just replacing the gasket might not be all you need, you probably need to resurface the manifold. This should only be about $50 but it will give you a flat surface. Lastly, if you are doing the passenger side which sounds like you are, it's going to be a bitch. You're probably going to need to tilt the engine block to one side. Huitt, I don't know how you did that in one hour.
Now that raises a question, why did you need to replace the gaskets? Did your headers warp or develop a leak? I have developed this exhaust leak at the manifold 3 times, fixed it the first time on the passenger side, now the pass and driver side both leak again.