header gasket replacement ??

[dukcaln]

So I find myself with a header gasket leak on passenger side...looks like a fairly easy job (see pic)... my questions are 1) is there a better gasket than most or are they all the same 2) do I need to completly remove the header or are the gaskets able to slide into place if I just loosen the bolts enough to pull the header back and slide the old gasket out and new gasket in the tighten down 3) never done a header gasket any tips or tricks?