How to reset a FortiAP 321C

Hello

I've managed to set a password (copy and paste) - maybe it was too long - on a FortiAP 321C and now I'm not able to login again .

I cannot find a reset button or other procedures in the docs. While it is not critical at them moment since the FortiAP is setup and working, there must be a way to reset one of those devices, right ?

Thanks for your help!

Frederik