In the Installing Add-ons in TBird entry, I put together a very comprehensive step-by-step list to install add-ons. All along I was think ‘there has to be a simpler way to do this.’  Well, there is according to this comment from CHR:

As far as I know, one could still drag & drop the extension from firefox to the thunderbird add-ons manager window to install the extensions right away.

Okay it cain’t be that simple, can it? Well I decided I would test this out and install Lightning (which I am still having trouble saving events/to-do tasks) via this method. So I found the add-on in the Thunderbird section of AOM and dragged the Install Now link from the green box into Thunderbird add-ons manager window.  At first nothing happened then a few seconds later the usual install dialog popped up.  I went through the steps and installed Lightning and then restarted Thunderbird.  Once I restarted there was Lightning installed and ready to go.  Now if someone can tell me what the heck I am doing wrong when trying to add tasks or events I’ll be able to do a write-up on the add-on.