[steve25]

Other than having the need to have jack stands or ramps to drive the front of the car up
on getting the exhaust manifolds off is most times the biggest adventure in using 4 letter words to express yourself!

plan on buying a long open end wrench that will fit your header bolts and grinding it down on the outside of its jaws to give you good access to the center exh port rear bolt where the headers make a sharp turn back to the firewall.
You may find the bending this wrench length wise into a bit of a S shape will help with access also.

Be sure that all of your new header bolts are good thread wise and make sure that all the bolt holes will accept a bolt being treaded in with just easy finger motion, so it may be a good thing in this regard to have 3/8" course bottom tap on hand in case its needed.

install all the header bolts for one side then install the gaskets, but what you want to do is to cut the gasket into 3 sections and then slot the bolt holes so you can just slip the gaskets in place by rocking the header as it hangs off of the bolts.

First and for most is to apply antiseeze on all of the bolt threads and its not a bad idea to give each gasket section a fine coat of the stuff also!
Its messy this way but if a gasket should blow out having to not use a single edge blade to scrape the old one off for ten minutes will make you smile!

After the motor has been run up to normal temp by driving it then let it cool down to the point that you can touch one of the heads and then retighten all the bolts, do this again after the next time you drive the car and all should be well!