Reverting from wordpress development version to mainstream version

You need to do a manual update as follows:

Backup both files and database of your site, to offline location.

Now, delete wp-admin and wp-includes from old location

Copy over wp-admin and wp-includes from new location

Copy (without subdirectories) all files from root of wordpress zip(tar) file.

More detailed instructions are here.

You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.