Who wouldn't know!? But for those who don't: Take off the back panel to your cell phone, then remove the battery, You should be able to see the sim card once you remove the battery.
a gadget known as card reader is there , it can easily connect any sim to a PC or a laptop and u could easily access to all information of sim card .this gadget is not so costly and it is very cheap...
Notify your new cell carrier of your current number, and request it for your new service.
*Actually an easier way is to save your address book contacts onto your SIM card and have the store helper...