You may not get enough clearance with the mentioned procedure. You may find the header hitting against the back edge of the firewall. Two methods of getting it off. First (hardest), unbolt the header from the exhaust pipe. Second (easier, at least for me), remove the studs for the last three head pipes (manifold). You will have more than enough room to replace the little gaskets. I would replace the studs with stainless steel metric cap screws, so future work will be easier. If fact do them all. Half the time the studs will back out anyhow due to rust on the nuts.
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.