Site Name Dash Issue, Please Help

Is there anyways I can change the format of my site’s title? Here’s an example:

Post Name – Site Name — Tag, Tag, Tag, Tag

I want to change that first dash, to a pipe |. Does anyone know how to change this? I’ve been roaming around my themes HTML files, but I can’t find anything. Thanks! BTW, I installed a plug-in that put my site’s name after the post’s name. Could I somehow edit that portion of the plug-in?