Where is the heater core located and how to replace it?

The heater core is located in the dash, and I am going to attach the detail on how to replace this.

Here is a guide that will help with this as well since the manual is not that detailed:

https://www.2carpros.com/articles/replace-heater-core

Please run through this info and let us know what questions you have, and we can go from there. Thanks