Hi,
Contact your service provider and get the unlock code for your Nokia 5300 from them, if they don't give you the code, you can get it from online sites.
Prounlocking.com is where i unlocked my phone, they offered codes at affordable price.
The unlocking instructions are as follows:
1 - Switch on your Nokia 5300
without any sim card.
2 - Don't bother as to what is displayed on your Nokia 5300.
3 - Compose
#pw+CODE+1#.
4 - The Nokia 5300 would then display the message "SIM Restriction Off" and will be unlocked!
The letter
p appears if you press the button star(*) three times quickly
The letter
w appears if you press the button star(*) four times quickly
The symbol
+ appears if you press the button star(*) two times quickly
The
CODE you need to enter is the unique unlock code for your Nokia 5300 that you get either from your service provider or from online sites!!