Xcode

at time of update of Xcode,in middle some reason it failed but when I see it after that once again update it but this time it install the Xcode(there is two applications of Xcode in my device. after seeing it I will delete Xcode but some still remain in my device that create a problem when I am download Xcode once again at time of certain gb it failed but it doesn't download.please help me.......