Posted By:
JoannGo to the URL of the single post you are in. In the middle of the URL is the word message. Replace it with the word thread.
As in:
blabbity/blab/blahblah/message/moreblahblah
becomes
blabbity/blab/blahblah/thread/moreblahblah
Joann
(Credit to Ted G. for cluing me in to that trick.)