First of all you need charles running
1 - Which charles running, try to log in to the PSN network, and go to charles (nav/auth) search in the field "CONSOLEID" and copy your id
2 - Go to TOOLS - REWRITE , and add a new rule to the PS3 auth server.
TYPE: BODY
In the First value box, put your ID and in the Replace value box, put another ID of other PS3.
WARNING: DONT WORK WITH RANDOM IDS.
PD: 1 id works with a couple of PS3.