Você não pode instalar, no pacote são arquivos exe que você usa na linha de comando.
Opus-tools provides command-line utilities to encode, inspect, and decode .opus files. Opusfile provides application developers with a high-level API for decoding and seeking in .opus files. DLLs for the required libraries libogg 1.3.2, libopus 1.1.1 and openssl, are also included in the binary package.