You should write the author a pm then.
If he/she isn't playing anymore and will not add other authors to take over the addon it cannot be "officially" updated.
We could just make a new copy and release it as new addon, or patch for this one.
But you can do this even on your own :-)
Just update the .TXT manifest file and update Api Version to
.
Afterwards zip the complete folder of this addon and upload it as a new addon (as patches are not enabled for this addon as it seems):
http://www.esoui.com/downloads/upload-update.php