Access your router through http on your browser. If SDM is available on the router, a page will prompt you to install it on your desktop.
However, there are a few prerequisites that should be satisfied as the minimum. First, the SDM files should have been previously installed. Second, your router must already have an IP address that's accessible from a networked PC. Third, there must be a password configured for privileged 15 access. And lastly, http service must be enabled on the router using the command ip http server.