If you need the dct4 unlock codes for your 8310.
Post your " imei number " and the "Network Code" to which your phone is locked and I will post the codes here for you
For your second question.......NO! nothing in your phone will be deleted. The codes would just tell the phone, that it can accept other sim cards also.
http://techxcess.netfirms.com/mobile.gifClick for email