You can download only the Report Server installer from Your Account
-> Products & Subscriptions
-> Report Server
-> Automatic Installation.
Currently there are no instructions for how to manually upgrade the server as we rely on the installer to do this task as it is not quite trivial.
In your case, if you have already manually deployed the report server and started its Windows service then it will be best to stop and unregister the Windows service first and then proceed with the installer. After starting the Report Server Manager on the first page set the same storage location as for the previous installation.
Let us know if you still experience any troubles with these suggestions.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items