blog will describe the prerequisites and things need to do to update to windows 8.1. So have you updated your phone to windows
8.1, if yes and you are a developer then follow the below steps
It’s important to test your Windows Phone apps on a real
phone. Before you can deploy apps to your Windows Phone, you have to register
the phone for development. Register or unregister a phone by using the Windows Phone Developer Registration tool
(phonereg.exe). After you register your phone, you can install, run, and
debug apps that target Windows Phone 8.1, Windows Phone 8, or Windows Phone OS
7.1 on the phone.
The Windows Phone 8.1 development tools are included with
Visual Studio 2013 (Update 2 or later). If you already have Visual Studio 2013
installed, use the download link to install Visual Studio 2013 Update 2 RC.
Download and install the Windows 8.1 Developer tools from here.