Iphone 5 Software Update Issue iOS 8.3?

I have an iphone 5. I'm having some trouble installing the iOS 8.3. I go to setting > General >Software update > Install now > Then agree > But nothing happens. It just takes me to the front page. I have checked my usage I have 4.6 GB left. I have pressed restart but I that changes nothing. Does anyone know how I can fix this issue?

It may require you to be on a Wi-Fi connection.

It also needs the battery to be well charged or a charger connected before is starts.

You need to be using either a Wi-Fi connection or do it thru iTunes. You didn't say how you were doing this, but wanted to throw this out there. If you are using one of these, then you're likely going to have to either take your phone in for them to update it, or else open a troubleshooting ticket with Apple to help you.

You need to enable Wi-Fi and Data connectivity to enable the download and installation. Of IOS. You also need to have enough space in the device to enable the installation to work.