Exhaust sealing o rings

Hello,

In order the replace the exhaust manifold gasket. First you will have to remove the bolts that keeps the manifold mounted to the engine and well as at the pipe.
Keep in mind that those bolts can be seized due to all the heat. This will require using penetrating oil to loosen them up.

After removal of the bolts the exhaust manifold can be removed from the vehicle. This will allow you to discard the old gasket. Be sure to clean / scrape off any residue left on the engine.

Then you will be able to install the manifold using a new gasket.

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

https://www.2carpros.com/articles/how-exhaust-systems-work