To make reset your character has to:
- Be 400 level
- Has 10kk zen * resets amount
- Go to Account panel -> Reset on the website
- Click the "Reset" button (available when you meet the reset requirements) in the last table column for the character
After reset you will get 500 (600 for DL/MG/RF/GL) * resets amoun free points and character's level be 1.