The password is encrypted in database and there is no way to retrieve your lost password. You can only set new password by changing password column of the "iu3_users" table for your user's record. Please note that passwords are encrypted with md5, which is one-way encryption (can not be decrypted), so you need to store md5 hash in the database, instead of raw password.

You can use this tool to encrypt your new password in md5: http://pajhome.org.uk/crypt/md5/