To insert simcard in your phone you need to take care of two things..one is the sim size and another is whether the phone is unlocked to accept all sim network. Regarding the sim size try to get the desired sim size first. Check whether the phone is not locked with any other different network. If so,it will not accept the sim that you enter. To unlock the phone visit Superunlockcodes.com and get the unique unlock code along with free unlock instructions. Once you satisfy the above conditions switch OFF the mobile and remove the back panel and battery you can find the sim slot below the battery...insert the sim in the desired position and replace battery and backpanel.