Reset search preferences to default

Hello,

On 3.6.0, can anyone tell me how to restore the default search format
(as set in $DefaultSearchResultFormat in RT_Config) to a user after
they have modified their own search preferences? I have users that
have modified their search format and are now missing fields that
they can’t add back in because there is no advanced option to do the
required customization.

Any help would be greatly appreciated!

Thanks,

Fran