Delete existg '/forum' files/folders b4 upload 'upgrade' files/folders ?

[akm]

We need to upgrade from MyBB 1.8.7 to MyBB 1.8.15, and from the upgrade instructions (old greycells) are not able to determine if we need to delete all existing files & folders from our /forum directory b4 we upload the 'upgrade' files & folders, or just upload & replace (not delete existing) and leave any not replaced files & folders in the /forum directory?
Advice?

[Wires]

Unsure why you think you need to delete anything. You'll need to do a full upgrade as you're more than one point below the newest version. Update and overwrite the existing files with the newest version, then visit the /install/ directory and follow the instructions there.

https://docs.mybb.com/1.8/install/upgrade/ for more instructions.

[akm]

Thank you for the info!
For some reason (old greycells) didnt fully see/understand this info in the Mybb instructions we viewed.
"1. Upload all of the files and folders inside the package (from inside the Upload/ folder if using the full package), including the install/ folder (if it exists), overwriting the existing copies of the files in your file system."
So, we will assume it is ok to upload (in this case with FileZilla) the /Upload files & folders, allow them to overwrite existing files, and LEAVE (not mentioned in the instructions) any other existing files that do not match the /Upload files.
Will (after backup /forum) give it a try.

Unsure why you think you need to delete anything. You'll need to do a full upgrade as you're more than one point below the newest version. Update and overwrite the existing files with the newest version, then visit the /install/ directory and follow the instructions there.
https://docs.mybb.com/1.8/install/upgrade/ for more instructions.

[akm]

Uploaded '/Upload' files (with FileZilla 'overwrite') and (with a few 'extra' clicks seemingly needed at the 'Updating Database' phase) all (1.8.7 to 1.8.15) seems to be ok.
Not a very 'fancy' (aesthetics) forum, but all the original visuals (and posts) seem to still be (coordinated with database) there.
The upgrade instructions at https://docs.mybb.com/1.8/install/upgrade/ are simple (even for
these old greycells) and (even though dont specifically mention no need to delete any existing '/forum' files : ) ) very helpful !