here is how to change your lost password:
1. SSH to your VPS
2. run mysql on your asterisk box. (the default root mysql password in elastix is eLaStIx.2oo7 )
[root@asterisk /]# mysql -u root -p
3. use asterisk database.
mysql>use asterisk;
4. update admin password in ampusers table.
mysql> update ampusers set password="NEW_PASSWORD" where username="admin";
NOTE: change "NEW_PASSWORD" to your new password.