First you need to generate the stems and export them as audio.
Then collect all the stems you are interested to open with SMP into one folder (as well as the SMP stem files).
In SMP you go to the upper right hand corner "side panel". In the side panel select audio and navigate down to the folder with stems but don't open the folder, right click on the folder and there will be an option "open as stems", and they will all come up as stems in SMP. There may be some more information in the help documentation.

The thing I find easy with SMP is that it aligns all stems correctly (one can do the same in a DAW but when I try it in SO they are all aligned wrongly)


BIAB 2025, Studio One 7 Pro, Song Master Pro, Win11 Home. i7-9700K CPU, 32GB, ESI MAYA44eX, Guitar Pro 8, Transcribe, (EZKeys2, Superior Drummer3, EZBass, EZMix3)
Amateur: fiddle, guitar, vocal, beginner on bass.