Modify TinyMCE in the Theme

I would like to change the TinyMCE skin/theme in my WordPress theme. My website is https://dcjtech.info/ and I made my own theme (and most of my plugins). However, despite me being knowledgeable enough to make my own theme and some plugins, I have not figured out how to change the TinyMCE skin.

NOTE: I have the latest versions of WordPress, BBPress, and Buddypress. I use the TinyMCE editor (with the same configuration) in both WordPress and the BBPress forums (backend and frontend).

I need to figure out how to dequeue “skin.min.css” and “editor.min.css” or at least declare that the TinyMCE skin/theme is in my WordPress theme folder. It would also be great to remove the style-sheets that are in the head of the iframe within the TinyMCE editor. I have used the mce_css hook to remove one unneeded CSS file. However, I cannot use the mce_css hook to replace the other CSS files with ones in my theme.

If there was a way to make the TinyMCE editor become a plugin and have all of the TinyMCE files under “plugins”, that would also help. That would still allow me to edit the skin and retain customizations across WordPress updates.

To clarify any potential misunderstandings, I am wanting to change the appearance of the TinyMCE editor itself. I already use “editor-style.css” successfully for styling the contained text in TinyMCE.

I do not want to edit core file since doing so is not recommended and because GoDaddy (my hosting service) updates the WordPress core when new updates are released.

Thanks in advanced for your time, thought, and help.