I have seen plenty of threads where someone "modified" a posting they had made. If I wanted to do the same on one of my posts how do I do it??

you will see a button that says "edit message".  Click on that and you will be able to edit (but not delete) your post.

You only have about a 24 hour window of opportunity to do so, however; then it is carved in stone, so to speak.

You have 24 hours to edit your post.  Unfortunately, if you are moderated, the time your message spends waiting to be approved counts in your edit window.

I was looking for the edit button ! I knew my eyes are going bad but....

Didn't realize there was just a 24hr period to decide. That explains why I couldn't find the button !

Thanks

no wonder my post was posted, but didn't show up until 24 hours later...I don't think they got the message I sent right after to delete my last reply. LOL