title: How to change Python version of existing conda virtual environment?
body: <p>I created a conda environment with Python version 3.8, but it doesn't support matplotlib... So I am looking for something like this to change the Python version: <code>conda env my_env update to python=3.6</code>. Is this possible or do I need to recreate the environment?</p>
  <p>I have miniconda installed.</p>