Are you Installing A Sound Set (https://www.thewritescore.com/docs/sibelius-templates/installing-a-sound-set/) and can't find the Users' Library folder? Do this:
Hold Option and Use the "Go" Menu to Show Library
Holding down the Option key will show the "Library" directory as an option in the Finders Go menu. The other nice thing about the Go menu is that after you have accessed ~/Library on multiple occasions, it will start to appear in the "Recent Folders" submenu for easy repeat access. (See attached image.)
A couple more methods for showing the Library folder can be found at Access hidden User Library files (https://helpx.adobe.com/x-productkb/global/access-hidden-user-library-files.html).
This thread really helped me to create a sounds folder in the right spot, drag the template file (VDL Soundset 7.0.xml) into the folder.
The read me says to 1) click on "new" 2) name your configuration to your liking 3) Activate kontakt player (hover), and double click the field under "sound set" to get the sound set drop down menu, select "VDL soundset 7.0"
I am running Sib 8, VDL 2.5.5 and kontakt 5...when it says double click field under sound set, are you referring to the field inside of Sibelius...because the only thing double clicking does, is prioritize the order of my active devices by soundset. I hope this makes sense, and i hope you can help...but more importantly I hope this hasn't been covered in a thread and Ive missed it.
Click on the name of the currrently-showing sound set. See attached image, elements in green.