Tvheadend

Very new to using TVHeadend in Firefox and I was trying to set up the system to link to my WeTek Play 2 box in LibreELEC setup. Had it working once and then wanted to start again with the wizard, put in a username and password into the Administrator box then messed up and it wont let me back in. It doesn't recognize my password, is there any way to reset it. I have taken all the cookies from Firefox and did the same in Chrome, no help. can anyone give me some advice on how to get back into the TVHeadend system. Please.