I have already created the Information Architecture site setup for our SharePoint 2013 environment. So I have the top level portal, with sub sites, and web's.
I then just created a custom Site Template that I want to retroactively apply to those skeleton's that I have setup.
There is no content on these sites yet, but we have added permissions, so I don't want to blow these sites away and have to re-create them. Is there a powershell command that will let me install the wsp to already existing sites?