Im not an expert on the matter so take everything with a grain of salt
Either try to find a compromise, or mabey have a break from each other so they can come to a suitable conclusion without having rushed and emotional decisions , or if the situation is rly rly bad and they are to break apart it's better to do so in good terms rather than having it as a really bad memory that haunts you
I've seen several freind groups big and small quarrel and 1 person separating from it but they always seem to come to good terms afterwards whether it be in a week a year or 2, I can't say for certain if it'll be the same as I feel the culture from where I'm from also may factor to. These aren't great solutions in any way I'm just telling some ideas based on my past experiences and ideas, sry if I couldn't help

I might need to point out the reason why one wishes to unfriend the other is because they're a bad influence . I'm only gonna point out the parts that I think I'm allowed to . The other parts feels like it's to be kept a secret