$ solc-select --help
usage: solc-select [-h] {install,use,versions} ...

positional arguments:
  {install,use,versions}
                        Allows users to install and quickly switch between Solidity compiler versions
    install             list and install available solc versions
    use                 change the version of global solc compiler
    versions            prints out all installed solc versions

optional arguments:
  -h, --help            show this help message and exit

$ solc-select versions
No solc version set. Run `solc-select use VERSION` or set SOLC_VERSION environment variable.
0.3.6

$ solc-select install 0.8.0
Installing '0.8.0'...
Version '0.8.0' installed.

$ solc-select use 0.3.6
Switched global version to 0.3.6

$ solc-select versions
0.8.0
0.3.6 (current, set by /Users/artur/.solc-select/global-version)

$ solc --version
solc, the solidity compiler commandline interface
Version: 0.3.6-b96bf446*/Release-Darwin/appleclang

$ SOLC_VERSION=0.8.0 solc-select versions
0.8.0 (current, set by SOLC_VERSION)
0.3.6

$ SOLC_VERSION=0.8.0 solc --version
solc, the solidity compiler commandline interface
Version: 0.8.0+commit.c7dfd78e.Darwin.appleclang