If the member claims to never have received an email with a password, make sure that the spam folder was checked and that the email address was entered correctly.
It is also possible to manually change the member password under edit members.
IMPORTANT NOTE: To prevent fraud it is utmost important you make sure the person who requests a password reset is really the person (s)he claims who (s)he is. With the right email address and password anyone can log into the system. Best practice: check the answers from the join survey and ask the person a few control questions before you change the password via edit Members.