Take a looking at this:
https://docs.microsoft.com/en-us/skypeforbusiness/troubleshoot/server-install-or-uninstall/clean-uni...
I turned the above into this script
#!/bin/zsh
# https://docs.microsoft.com/en-us/skypeforbusiness/troubleshoot/server-install-or-uninstall/clean-uninstallation
killall "Skype for Business"
rm -rf /Applications/Skype for Business.app
rm -rf /Library/Internet Plug-Ins/MeetingJoinPlugin.plugin
defaults delete com.microsoft.SkypeForBusiness || true
rm -rf ~/Library/Containers/com.microsoft.SkypeForBusiness
rm -rf ~/Library/Logs/DiagnosticReports/Skype for Business_*
rm -rf ~/Library/Saved Application State/com.microsoft.SkypeForBusiness.savedState
rm -rf ~/Library/Preferences/com.microsoft.SkypeForBusiness.plist
rm -rf ~/Library/Application Support/CrashReporter/Skype for Business_*
rm -rf ~/Library/Application Support/com.apple.sharedfilelist/com.apple.LSSharedFileList.ApplicationRecentDocuments/com.microsoft.skypeforbusiness*
rm -rf ~/Library/Cookies/com.microsoft.SkypeForBusiness*
rm -rf /private/var/db/receipts/com.microsoft.SkypeForBusiness*
rmdir ~/Library/Application Scripts/com.microsoft.SkypeForBusiness
find -f /private/var/db/BootCaches/* -name "app.com.microsoft.SkypeForBusiness*" -exec sudo rm -rf {}
exit 0
