Update PEP 101 wrt new tech for EOL-ing a branch.

pep-0101.txt

@@ -914,6 +914,10 @@ else does them.  Some of those tasks include:
         Doc/tools/static/switchers.js
         Doc/tools/templates/indexsidebar.html
 
+  Note that the best way to do this is to make the change in the current
+  `master` branch, then backport to the other active branches.  (This will
+  hopefully pacify the current state-of-the-art nannybots.)
+
 - Freeze the state of the release branch by creating a tag of its current HEAD
   and then deleting the branch from the cpython repo.  The current HEAD should
   be at or beyond the final security release for the branch::
@@ -927,6 +931,12 @@ else does them.  Some of those tasks include:
 
         git push upstream --delete 3.3  # or perform from Github Settings page
 
+- Remove the release from the list of "Active Python Releases" on the Downloads
+  page.  To do this, log in to the admin page for python.org, navigate to Boxes,
+  and edit the `downloads-active-releases` entry.  Simply strip out the relevant
+  paragraph of HTML for your release.  (You'll probably have to do the `curl -X PURGE`
+  trick to purge the cache if you want to confirm you made the change correctly.)
+
 - Add retired notice to each release page on python.org for the retired branch.
   For example:
 
@@ -938,10 +948,6 @@ else does them.  Some of those tasks include:
   list (https://devguide.python.org/devcycle/#end-of-life-branches) and update
   or remove references to the branch elsewhere in the devguide.
 
-- If necessary, create a PR to update the supported releases table on the
-  `downloads page <https://www.python.org/downloads/>`_.
-  (See https://github.com/python/pythondotorg/issues/1302)
-
 - Retire the release from the bugs.python.org issue tracker. Tasks include:
 
     * remove branch from tracker list of versions
@@ -957,6 +963,10 @@ else does them.  Some of those tasks include:
   wholesale changes to existing issues until the migration process is
   clarified.
 
+  In practice, you're probably not going to do this yourself, you're going
+  to ask one of the bpo maintainers to do it for you (e.g. Ezio Melotti,
+  Zachary Ware.)
+
 - Announce the branch retirement in the usual places:
 
     * mailing lists (python-committers, python-dev, python-list, python-announcements)