I just bought this cherokee and noticed that my mileage and power were lacking, I checked the engine while it was running and noticed an air leak sound, and smelled exhaust so I took some water and could see mico bubbles coming from around the gasket where the header meets the block. How hard is it to do this job myself, I am kind of an amateur home mechanic, I can do simple things(change spark plugs, thermostat, oil etc) but have never attempted a project of this level before.

I would eventually like to replace the headers and exhaust but its not in the cards monetarily speaking, so for now I would need to pull the old headers replace the gasket and put the old ones back. Is this realistic for someone with my experience level or should I seek professional help on this?

 

Its not hard, providing you have a repair manual (auto store of your choice, $20-30 bucks), and have turned a wrwnch or two before. The manual will show you the torque sequence so you can properly get it off, and how much you need to torque it down afterwards.