How to delete manually installed 1.3.8a and automatically install 1.5.0?

I have 1.3.8a installed manually on the rootfolder where there are addon domain websites. I need to to upgrade. You guys will probably recommend to install 1.5.0 manually.

I'd like to know how to delete old version without killing addon domain websites and and install automatically thru simplescript a newer version, 1.5.0 just in case?

Is it just:

1. back up db and the zc website
2. delete all zc files, folders (in subfolders the addon domain website folders and files exist)
3. install on the main domain or root folder the new zc version automatically?
4. do all customizations ....................?

The reason is I was not successful with winmerge comparing tons of files, previously. So I might do it again: install automatically anew, then customize. Probably stupid, but how i did once before.

Any suggestions?

Thank you guys all, in advance.

I can't see why the contents of the add-on domain folders will have any effect on a Zc installation in the root. The addon domain folders are separated from what else goes on in the root - simply by the fact that they are separate folders.

Of course I am open to correction here, but I would think that if you upgrade the 1.3.8 version currently located in the root, it should have no effect on what is contained in subfolders NOT related to the root install ation of zc... and the subdomain folders are such folders.

As with any upgrade, at any level, full backup is required anyway, so your protection is in the solidity of your backup before you do any upgrading.

As you said already, we recommend doing manual installs. Especially when you've got other things in your hosting account already.