A manual 7.5.7 upgrade from a very customized UBBThreads 7.5.6 was quite easy.
I just unzipped the original 7.5.6 & 7.5.7 archives in to their own directories on a local computer. Then compared each directory/file in
Beyond Compare to view the difference. Then, in another window, I modified my customized UBBThreads files with the differences. Next, I tested out my work on a local sandboxed server. Lastly, I read through any txt files in the install directory to see if I was missing anything or if there were database changes that needed to be done -- finding no "altertable" file for 7.5.6, there was no database mucking around to be done
This upgrade was quite simple and straight forward as usual.