The bolts that go into the cylinder head shouldn't be to bad. The bolts that hold the exhaust pipe flange to the manifold could be another story. I'd get a can of good penetrating oil and start soaking everything real good before you tackle the job. You will more than likely need to use heat on the nuts for the flange. Take your time and if your unsure round up some help. The method I always use is to heat the nut red hot, then get a good 6 point socket on the nut and gently try and loosen it. It may move some,then snug it back up. You may have to do this a couple times to get things going. Just be careful because it will be real easy to snap things off.

Good Luck
Don