Removing packages from local pypi index depends on type of pypi index you use.
removing package from devpi
index
devpi
allows removing packages only from so called volatile indexes. Non-volatile are "release like" indexes and removing from them is not allowed (as you would surprise users depending on released package).
E.g. for package pysober
version 0.2.0:
$ devpi remove -y pysober==0.2.0
removing package from public pypi
is described in the answer you already refered to.
removing package from other indexes
Can vary, but in many cases you can manually delete the files (with proper care).