WOW, from the looks of that picture, you could probably give it a swift kick and it would fall off!!! That is some uhhh, should I say shocking,:roflmao: looking rust for this Texan.
One tool I found to be handy is a sawsall (electric)
http://compare.ebay.com/like/110357412592?var=lv<yp=AllFixedPriceItemTypes&var=sbar
They cut through steel like a knife through melted butter. But are not good on cramped spots.
I have never seen a shock with a boot quite like that, But I almost never replace shocks, they seem to last forever down here (Houston). You just use the steel washers and bushings that come with the new shock and trash the old boot/bushing. One threaded nut is top side, on top of a steel washer and rubber bushing, bottom side of the top shaft gets a steel washer then a rubber bushing, jeep sheet metal is sandwiched in the middle. Take the top nut off, then the two bottom bolts, and the shock is off.
I have had pretty good luck soaking rusted stuff daily for a few days in PB blaster before I try to remove them, but if the rust is bad enough (like yours in that picture) you can still twist the nut off and or break the shaft, what is left of it. Then you need the next level of skills if it is a welded nut with the rusted junk still stuck in it!!!! So unless you want to learn how to cut and weld now and buy the tools for that, or do simple sheetmetal work, like drilling sheetmetal, and so on, you should have a local shop do it. Not Walmart, but a real hard core shop that can cut and weld too. You could try the bolts and nut after soaking in PB Blaster to see if they come loose real easy first?