ibProArcade MySQL script request

Hi, I am wondering if anyone can help me.

I am using the latest version of ibproarcade and for the past while have been using the setting to allow games to store every high score that a user gets.

Due to requests I have now changed to the setting which allows only the highest score a user gets to appear on the high scores.

However I am having trouble finding a way to delete every users additional scores from the high scores to leave only their highest score. Due to my lack of mysql knowledge i have been manually deleting scores via phpmyadmin but this is ridiculously time consuming.

I am looking for help creating a script that will accomplish the following:
To delete all scores that are less than their highest score of each user from the database.

I assume the function should probably be something like this: (although I don't know if it is possible)
DELETE other rows from table 'SCORES' of 'USERID' IF 'USERID' has 'SCORE' value greater than value of 'SCORE'.

Thank you very much in advance, and I hope this is understandable.