Z500 questions

Hi.
I was wondering. I used the Z105 service software to unlock my phone.
But is there a more recent software specific to the Z500 ?
If so could someone please send me it ? pm me or something.
And nother question. How can i go about upgrading the firmware on this baby ?
Are there any public services for upgrading or can i use the service software for this ?
The questions that naturally follows then is . Where can i find the firmware if there isn't a public service for this ?

Thanks !
Regards, Stefan