Changing sound patches without changing staff labels

I have another question that I am not sure how to ask/search, so, if the question is answered may be answered elsewhere, I apologize in advance. So, here goes:

I have a score for SATB chorus and organ all set up and engraved the way I want it. I would now like to extract audio samples for part-predominant rehearsal parts of the choral parts. So, there will be five audio files extracted, one with S predominant, one with A predominant, etc, and then a final one with all voices balanced. I, however, do not generally care for the quality of any choir samples – they are generally too slow in articulation, and also too dark in quality to sing with and over for rehearsal. I prefer to use a double reed sound (oboe and bassoon).

How do I change the sample from choir to oboe in the choral parts without doing it in setup mode? I cannot figure out how to do it within play mode. I have watched a couple videos, but none seem to do explain exactly what I want – Telling me to watch a video is fine if it answers the question and gives me a good process.

Go to Play Mode, select your “instrument” f.e. Soprano. On the panel to the left click onto the squint “E” icon. A new window will open. In this window you can assign any sound of your libraries (to the right) to your “Soprano” Instrument.