How do I instal iOS 9.3.1 on my iPhone 5S?

[IPT123]

Trying to install over wifi but see only " Update requested" and the wheel icon rotating very slowly. Been like this for more than 30 mins.

 

[kch50428]

Try connecting to iTunes.

 

[IPT123]

Problem resolved itself overnight. IOS 9.3.1 successfully installed this morning.