There are two ways for deleting your old provisioning profiles from Xcode.
1. Xcode Preferences
2. iPhone Configuration Utility Software.
- Xcode Preferences -> Go Xcode -> click on left hand side top toolbar option Xcode -> Click Preferences -> Accounts, select your account, and hit the refresh button on the bottom left corner under the provisioning profile list.
By doing this you can delete your provisioning profiles.
- iPhone Configuration Utility Software -> Install this software -> Open Software -> Provisioning Profiles -> find list of your all profile -> Press Backspace button, it will ask to delete provisioning profile ->Click on delete provisioning profile. So it will remove it from your all existing Xcode application and even from your PC.