How erase master password SSD disk


I bought a Sandisk 960GB SSD 2 years ago. It works very well. I recently tried to put a password on it in Toshiba Qosmio G50
I set up Master and User. However, I can no longer delete the Master password. I have a message with the wrong password. The User password enters and works, the disk normally can use the disk.
How to remove Master password. Data on the disk is not necessary

My model is: SDSSDA 2,5" SSD DRIVE