explaining commands for updating owncloud

@DeepDiver1975 and @LukasReschke: Thanks for your comments.
Explaination is rather longish now. Hope it's still okay.

admin_manual/update.rst

@@ -16,17 +16,28 @@ those steps:
 5. If you installed ownCloud from a repository, your package management
    should take care of it.
 
-Assuming your owncloud installation is at ``./p/`` and you wanto update to version 4.5.5, you could do:
+Assuming your ownCloud installation is at ``./owncloud/`` and you want to update to the latest version, you could do the following:
 
-``rsync -a p/ p_bkp`date +"%Y%m%d"`/``
+Use rsync in archive mode (this leaves file owner, permissions, and time stamps untouched) to recursively copy all content from ``./owncloud/`` to a backup directory which contains the current date:
 
-``wget http://mirrors.owncloud.org/releases/owncloud-4.5.5.tar.bz2``
+``rsync -a owncloud/ owncloud_bkp`date +"%Y%m%d"`/``
 
-``tar -xjf owncloud-4.5.5.tar.bz2``
+Download the latest version to the working directory:
 
-``rsync --inplace -rtv owncloud/ p/``
+``wget http://mirrors.owncloud.org/releases/owncloud-latest.tar.bz2``
 
-``rm -rf owncloud-4.5.5.tar.bz2 owncloud/``
+Extract content of archive to ``./owncloud_latest/``. 
+
+``mkdir owncloud_latest; tar -C owncloud_latest -xjf owncloud-latest.tar.bz2``
+
+Use rsync to recursivly copy extracted files (new) to ownCloud installation (old) using modification times of the new files, but preserving owner and permissions of the old files:
+**WARNING**: You should not use this [--inplace] option to update files that are being accessed by others *(from rysnc man page)*
+
+``rsync --inplace -rtv owncloud_latest/owncloud/ owncloud/``
+
+Clean up.
+
+``rm -rf owncloud-latest.tar.bz2 owncloud_latest/``
 
 Upgrade
 -------