Sony Ericsson k530i on 3 network - unlock ?

Purchased a sony ericsson k530i from three store. Has Skype, MSN, google as standard. I want to unlock phone to use on O2 network for a while. What is the best way of doing this? If I unlock the phone, will this have any effect on the three network services when using 083 sim card again?

Remove the simlock from your SonyEricsson mobile phone by code.
No need for cables or any difficult software

Your IMEI code: Type *#06#
The locktype on which the phone is locked: Type <**< and write down which lock is locked. (Where '<' left menu button; if you have joystick like K750i push down instead of left)


(p.s. another way to check your locks:
Type: >*<<*<* then choose 'Service info' and then go to 'Lock info')

Get your SonyEricsson unlock code off the internet, You may have to pay to get it
You can also unlock by using the cable that came with the phone and some software.
You should be able to use FURIOUS GOLD