I forgot to mention about installing new Snippets when you are still using the old one. While it's not yet recommended to replace old Snippets with the new version you should be able to install and run both of them.
To do this you have to rename the app bundle of the old version in Applications directory. Just open Applications directory in Finder, locate Snippets, press enter and type the new name. I use "Snippets 1", you may choose whatever you want.