Upgrading MySQL 5.5 to Percona Server 5.5 or newer on Ubuntu 12.04

On Ubuntu 12.04 the following packages need to be uninstalled;
mysql-client mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server mysql-server-5.5 mysql-server-core-5.5

an easy way of replacing the standard MySQL 5.5 with Percona Mysql 5.5 is:
Configure the Apt repository:
http://www.percona.com/doc/percona-server/5.5/installation/a pt_repo.html

$sudo service mysql stop <-- make sure MySQL is fully stopped. For some reason the uninstall process (below) will not stop MySQL and there will be LOCK issues with the datadir when Percona Server starts. $sudo apt-get install percona-server-server-5.5 percona-server-client-5.5

It will uninstall the needed packages and replace them with Percona:

The following packages were automatically installed and are no longer required:
linux-headers-3.2.0-23-generic linux-headers-3.2.0-23
Use ‘apt-get autoremove’ to remove them.
The following extra packages will be installed:
percona-server-common-5.5
Suggested packages:
tinyca
The following packages will be REMOVED:
mysql-client mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server mysql-server-5.5 mysql-server-core-5.5
The following NEW packages will be installed:
percona-server-client-5.5 percona-server-common-5.5 percona-server-server-5.5
0 upgraded, 3 newly installed, 7 to remove and 3 not upgraded.