Ripping Atmos

Hello folks. I’ve been entertaining the idea of doing a new audio mix for a movie, with total music replacement. Ideally I’d have isolated speech and sound fx, so is there a way to get the stems from an Atmos mix, either disc or streaming? (I would be willing to get a uhd disc drive for PC, if such a thing exists, and it would be of use.)

I’m not too familiar with its methodology so please correct me --rather than mixing the various audio to mono, stereo, surround, etc. Atmos instead has an unlimited number of isolated elements that are combined to the speaker setup indicated by hardware. Are the audio elements divisible by software before they go through Atmos processing? Otherwise I’d be using the center chanel of 5.1 which would not be ideal but possibly workable.