It seems you have to replace the whole display assembly, which is about $200. Hope you could afford it. After googled, you can find the new part from [http://www.amazon.com/Samsung-Galaxy-Black-Assembly-Models/dp/B00CTPWSW2|Amazon] or other [http://www.etradesupply.com/oem-samsung-galaxy-s4-gt-i9500-lcd-screen-and-digitizer-assembly.html|online store]. But please make sure the new screen is original before purchasing.