To install or upgrade to the latest version:

pip install -U simplere

To install under a specific Python version (3.3 in this example):

python3.3 -m pip -U simplere

You may need to prefix these with sudo to authorize installation. In environments without super-user privileges, you may want to use pip‘s --user option, to install only for a single user, rather than system-wide. If you use the standalone pip programs, you may also need to use pip2 or pip3 version-dependent variants, depending on your system configuration.