1. Download AdbDriverInstaller.rar from support and run it in order to get adb drivers installed
  2. Download VRoot_1.7.3.4863_english_cid1005_7337ba1e_89.exe from support and use it to root the phone
  3. Download OTSmart_v1.0.0.723.rar or newer, run it, select HTC DESIRE 310 from the models list, check Remove SIM_LOCK, press CONNECT and if all is ok you should have the codes displayed soon