Hello,
The instructions are the ones I just gave you here. There is nothing else to it.
Other material that you can also review: https://www.dashed-slug.net/developers-coin-adapters-api/
There is also some info in the documentation under the “Adapters” section.
Follow the instructions and ask me if you get stuck.
Also, you do not need to edit any files. I would recommend that you create your own adapter class, and add it into a plugin file in any way you see fit. Just remember to make the code include/require the class file on the wallets_declare_adapters action, as discussed above.
with regards