Yeah, I get that, most annoying.
Press the icon until it starts shaking, like when you want to move it. Then you should be able to hit the 'X' to delete it.
If that doesn't work, you will just have to let it download the update and then install.
Or download the update in iTunes and then install over the cable
There's no x to delete and when I try to install it again through the store, it says it's already installed
Try rebooting your phone. See if that allows you to delete it or if it will complete dling where you can then delete it.
Neither work, thanks for the xontinued help