What to do With Plugins in SketchUp 2013?
So now that you have upgraded to SketchUp 2013 you should be facing the question: What to do with SketchUp's plugins in this release. After all, when you started the new software for the first time, it likely only had the default plugins installed that Trimble released with it. But there was also a new toolbar button for the Extension Warehouse! At this time, you have a few options. Let's look at them:
A) You are upgrading and you had plugins installed in the earlier version
With the new Extension Warehouse and the SketchUcation Plugin Store now available, which both include one-click install and easy updating, it makes most sense to get plugins that are hosted in these places through the respective installers. So even if you had installed specific plugins in a previous version of SketchUp, I would recommend to go to these tools first to find them (instead of simply copying the Plugins folder). So here's my suggested order of...