Go to http://pypy.org/download.html and find the download link and wget/extract it.
wget https://bitbucket.org/pypy/pypy/downloads/pypy3.3-v5.2.0-alpha1-linux64.tar.bz2
tar xfj pypy3.3-v5.2.0-alpha1-linux64.tar.bz2
Preferably move it to /opt/ or /usr/local/:
sudo mv pypy3.3-v5.2.0-alpha1-linux64 /opt/
Install pip and virtualenv
wget https://bootstrap.pypa.io/get-pip.py
sudo /opt/pypy3.3-v5.2.0-alpha1-linux64/bin/pypy3 get-pip.py
sudo /opt/pypy3.3-v5.2.0-alpha1-linux64/bin/pypy3 -m pip install virtualenv
Use /opt/pypy3.3-v5.2.0-alpha1-linux64/bin/virtualenv
for everything afterward.