1. Go here
via your PS Vita and download the development suite.
2. Download the NES emulator (Via Attachments Below) (PSP-FCV0.52).
3. Download Vita Connect (Via Attachments Below) (*Note from source: The Vita Connect download also contains the source code of the program and a pre compiled program in the “VitaConnector/obj/x86/debug” directory. You may need to copy the dll files into that directory from “VitaConnector/lib” directory.)
4.Launch Vita Connect
5. Connect the PS Vita to your PC via it's USB cable.
6. Launch PlayStation Vita SDK on the PS Vita before clicking refresh.
7. Click on “refresh devices”
8. Click on “connect to the device”
9. Click on “upload”
10. Restart PS Suite Dev on your Vita
11. You should now have a “Leaf” game
12. Launch this to play NES