1.Copy templates_redshiftOSL and templates_samblerOSL in [version_number]/scripts subfolder of your Blender installation, or in any additional path(s) for scripts you've set in User Preferences.
2.In Blender Edit -> Preferences -> Add-ons -> Install install Additional OSL Templates.py.
3.To use new templates go to Scripting in Blender and press Templates button in Text Editor Menu
4.Tabs should now appear in Templates and look like this