How to "properly" downgrade LibreOffice versions

I am using the stable LibreOffice PPA, which just pushed out 3.5.0 and I (foolishly) upgraded from 3.4.5.

Now my LibreOffice is broken, with all sorts of issues like icons and launchers not appearing, being unable to Alt+Tab or Alt+~, the Unity dock filling up with (broken) LibreOffice icons that do not disappear when files are closed, and random errors and crashes.

What is the "proper" way to downgrade the LibreOffice version so that all new files get purged?

• In case you want to install the older version and replace the current installation:

sudo apt-get remove --purge libreoffice-core libreoffice-common

sudo apt-get autoremove --purge

Then find the version you want - here, download the archive containing the multiple deb files and install them following the instructions contained in the help/readme.

(Source: here and here.)

• In case you want to test or use different versions at the same time, even without removing the main/current installation, you may follow this answer.

Because libreoffice has a bunch of additional packages that integrate it seamlessly into gnome/unity/ubuntu, a simple "reinstall libreoffice" isn't a complete answer and leaves things half-installed.

I think I got it now though. Here's what I did:

1) sudo apt-get purge libreoffice?

2) opened Software Sources, clicked the Other Sources tab and removed the libreoffice PPA

3) sudo apt-get update

4) sudo apt-get clean && sudo apt-get autoremove

5) sudo apt-get install libreoffice libreoffice-gnome lo-menubar

6) reboot the machine

This puts me back at LibreOffice 3.4.4 and unity integration seems happy again.