Move SSRS engine to new server, but keep same reporting databases

We have our SQL Server reporting services (2008 R2) setup as follows:

ServerA: contains the reporting services engine (including the report manager URL, web service URL and so on).

ServerB: Is the sql server instance that hosts the reporting databases for ServerA (ReportServer and ReportServerTempDB).

ServerA is EOL and will be replaced by ServerC. I have two questions:

1. How do we proceed to install Reporting Services on ServerC so that it points to the databases on ServerB.

2. How do we migrate the reports (and settings) from ServerA to ServerC.  Will this be automatic by pointing ServerC to the exiting databases on ServerB.

Thanks.