MySQL - Upgrading from 5.5 to 5.6
Backing up the database is a best practice right before upgrading to any version. You can use mysqldump, Xtrabackup, mydumper .

Replacing MySQL community packages with Percona Server packages should do the job just make sure to execute mysql_upgrade after starting up PS 5.6 the first time.


  Percona Server is a free, fully compatible, enhanced, open source drop-in replacement for MySQL®


Always check the error log after the upgrade.