Reset the password of multiuser account with root my daughter changed her password on out multi user tablet to a complicated PIN and afterwards forgot the PIN :-O ... My other daugther did this already with her account but used a pattern which she forgot. This was at least no problem because I could reset the pattern by the android recovery feature "too often wrong pattern - did you forgot your pattern, enter your google account" !!! No Problem, BUT with the PIN - this dialog does not apear .... you can enter es much wrong PINs as you want - the recovery button ("forgot PIN") does not appar on this device !!!

Anybody help? I've root rights with the main account, but what to so?
GOT IT - very easy:

Using your favorite Root - Only File Manager, navigate to /data/system/users

and the propriate users subdirectory (10 , 11 , 12 ...) and there just rename or delete the passwort.key file

After doing so - the account can be unlocked with easy finger wipe !!!

Hope that helps also others !!!