OneThird To upgrade your version of CMS, it is OK just to overwrite the file
To revert to the previous version on the contrary, it is OK basically just overwrite the old version
As a precaution, make a trail version up that you backed up the current database
If the operation goes wrong, please overwrite the previous version
For the sake of further perfection, and at the same time and to back up the current database, please been upgraded by copying the program set to local
In that case,
files/img
And the following
files/1/backup
The following files Please exclude (because it takes a long time to download, also unrelated to version up)