* Identify system folders in your webroot (`cms`, `framework`, `sapphire` and any additional modules).
* Delete existing system folders (or move them outside of your webroot)
* Extract and replace system folders from your download (Deleting instead of "copying over" existing folders ensures that files removed from the new SilverStripe release are not persisting in your installation)
* Visit http://yoursite.com/dev/build/?flush=1 to rebuild the website database
* Check if you need to adapt your code to changed PHP APIs
* Check if you have overwritten any core templates or styles which might need an update
* See [common-problems](common-problems) for a list of likely mistakes that could happen during an upgrade.
* "Micro" releases (x.y.z) are explicitly backwards compatible, "minor" and "major" releases can deprecate features and change APIs (see our [/misc/release-process](release process) for details)
* If you've made custom branches of SilverStripe core, or any thirdparty module, it's going to be harder to upgrade.
* The more custom features you have, the harder it will be to upgrade. You will have to re-test all of those features, and adapt to API changes in core.
* Customisations of a well defined type - such as custom page types or custom blog widgets - are going to be easier to upgrade than customisations that modify deep system internals like rewriting SQL queries.
