This walks through upgrading Pyblosxom from a previous version.
First, read through the What’s New documentation which includes pointers to users and plugin developers regarding changes between older versions and newer versions.
This is at What’s new in 1.5.3 (July 2013).
To be safe, install Pyblosxom locally (as opposed to on the server or over your existing blog) and test your blog configuration and plugins to make sure everything works with the new version.
pip install --upgrade pyblosxom
OR Using easy_install:
easy_install -U pyblosxom
First, activate your virtual environment, then use either pip or easy_install as above.