Forget my password and username, help

Hi, I’m Roberto, I’m new to the subject of mikrotik, I’ve really liked these devices, sorry for my English but I’m Latin. I have a big problem buy a mikrotik Routerboard RB2011UAS- 2HnD-IN but forget your username and password, can someone help me with this? Investigate that it should be done with netinstall, but I’m afraid since I’ve seen comments from users who have blocked their mikrotik

Reset To Factory Default Settings.
The administrator account can also be reset with this way.