How to update Drush to 5.x in Quickstart 1.0

There is nothing special about either version of drush, except for the quickstart addons (which have been maintained in drupalpro)

I suggest migrating to drupalpro, quickstart is based on ubuntu 11.04, and no longer has security support (or otherwise). If you're not a fan of unity, its pretty easy to change the desktop.

[Edit] Disregard this attachment. I forgot something in it. Correction to follow...

@blacklabel_tom, just run the following commands from the terminal to update Drush to version 5.8 and the Quickstart Drush commands to match:

cd ~/drush
git fetch
git checkout 7.x-5.8
sudo mkdir /etc/drush
sudo chown quickstart /etc/drush
cd ~/quickstart
git fetch
git checkout -b master origin/master
cd ~/.drush
ln -sf ~/quickstart quickstart
drush cc drush

Note that the Quickstart commands syntax has changed a little. Use drush help --filter=quickstart for an overview.