Backup your database and site
Make sure you have a complete backup of both your Magento database and your installation files. The changes are small that a problem during installation causes a big problem with your installation, but it is always good to have a backup available where your can rely on.
Disable Magento Compiler
If you are using Magento’s compilation mode on your store, you must first disable it. Go to System->Tools->Compilation. If the compiler status is ‘Disabled’, you are ready for the next step. If not, click the ‘Disable’ button on the right hand side of the screen.
Upload extension files
Unzip the downloaded extension package and upload the extracted files with your favorite FTP client to the root of your Magento installation.
Clear Magento cache
Navigate to System-> Cache Managment. Select all available 'Cache Types', select the mass-action 'Refresh' and click 'Submit' to refresh all caches.
Login into Magento Backend
After your refreshed the cache, you need to logout and login again.
When can I un-cancel an order
Only orders that have the status 'Canceled' can be un-canceled, only then there will be an extra button in the 'Order View Page'. When you click this button the order will be set back to the status 'Processing'.
What is updated when I uncancel an order
When you un-cancel an order the following items will be changes:
- Order status will be set to 'Processing'
- All ordered items will be set back to ordered items
- Stock will be updated for all items in the order