heater core removal

Unfortunately, you are correct that these are not the best to do, however, they are not the worst.

Here is a guide that will help with this:

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

Clearly that is not specific to this vehicle, but it does have good info that will help.

Below you will find the specific info that you need from the manual on this vehicle.

Please run through this info and we can go from there.

Thanks