new Mac Mini, can't login, can't change password in Options

I just downloaded SoulseekQT on my new Mac Mini OS Yosemite, and entered the incorrect password. I received a message stating it was wrong and to go to Options to make any changes. When I go to Options, it doesn't allow me to change anything, and I also can't remember my password even if I could.

What now?

When you go to the Options->Login tab, there should be a Login As button at the top (you'll need to click Disconnect before you can try logging in under a new username/password).