It might help to know that Mark Twain was satirically using that word to juxtapose its offensive nature with Jim being the ONLY good adult in the book. It wasn’t simply “a product of it’s time” or anything like that.
I’m not saying to belt it out loud and proud while reading the book, but at the very least Mark Twain was being deliberate on his usage of it and it wasn’t to be malicious and was in fact to highlight the humanity of Jim in the face of his oppression. Some will say that Twain fumbled on his execution by making Jim a characature of stereotypes, but, at least it was just mindless racism, for what that’s worth.
ETA: To actually answer your question though “n-word” gives all the context you need, no need to say the word, it’s history is strong enough to be fully conveyed by “n-word” in almost all contexts when being spoken by a white person especially.
Funny how that is only a thing when they’re running a “practically a Republican” ‘Democrat’ and not when someone who’s actually a leftist starts getting some approval.