You don't. That is a TV thing. The page is not the screen.
How you tell a story in each medium is an artifice. You are never reproducing all the elements of real conversation, all the halts and tics and repetitions, and all the banalities of everyday speech would be catastrophically boring on the page or on screen. So you create a stylized dialogue, and you use the stylistic tropes of the medium you are writing for. People interrupting and talking over each other works on the screen. It does not work on the page. It just requires too much stage direction, which distracts from the dialogue itself, and the reader does not experience the dialogue as overlapping because on the page the reader can only receive a single stream of words at a time. You just can't reproduce the effect that this would have on screen.
So, you stylize the conversation in some other way for the page. This can include dialogues that the reader can read but would be very difficult for an actor to say. (Harrison Ford is famously supposed to have complained to George Lucas "You can write this s***, but you can't say this s***" (or words to this effect).) The screen is not the page.
So come up with an alternate approach to the dialogue that gets the same message across about character and motivation without having people talk over each other. There are always multiple ways to get the character of a conversation across. You need to choose one that works best in your chosen medium.