1. Press the release button at the top of the phone.
2. Remove the back cover.
3. Lift and remove the battery.
4. Open the SIM card holder, remove the SIM, and close the SIM holder.
5. Replace the battery.
6. Replace the back cover.
full instructions with images ;)
support.t-mobile.com/doc/tm53765.xml?related=y&Referring Related DocID List Index=5&navtypeid=6&pagetypeid=7&prevPageIndex=1
edit:... here the direct url to the image showing how to remove it :)
A Nokia 2330 uses a regular Mini SIM card. So, You must decide the network to which you are going to access with the Nokia 2330. Once you have decided the network visit any retail outlet for the respective network and get a SIM card and start using it.
If the Nokia 2330 has been network locked to any other network, You need to unlock it in prior. You can unlock a Nokia 2330 safer and easier using unlock code. You can get the unlock code for a Nokia 2330 from http://www.theunlockspot.com/nokia-2330-classic/rs16wp9/ at affordable cost with easy unlocking guide. Good luck mate.