Back to the Help page.
Detox is for those players that want to change their class. You will
keep all of your equipment and be reimbursed for all your trains spent
on your class skills.
For non-mastery characters it costs 500,000 gold.
or mastery characters it costs 5,000,000 gold and 5,000 quest points
and a Mythic mastery item.
This is permanent and WILL NOT be undone.