Here are the 3 files you need & a few pics of the menu screen to help. I don't have first hand experience with the nano 2 model, but have set up both nano & duo.
Make sure you write down your satellite lnb & switch settings before you load anything because once these files are loaded everything goes to factory default.
You lose all scanned channels & settings.
Format a usb drive in fat32 on your pc, extract the files & copy them to the usb drive. Only the 3 extracted files.
Plug in your usb drive, go to menu>utility>usb>autodetect>OK & begin downloading by highlighting the file & press OK.
First load the factory file(8.05 NPN) & wait for reboot & save to return to menu.
Then load the new file (another NPN) & wait again.
Then load the new dongle file(2.0.17) & wait again(with the dongle connected & powered of course).
When everything has been loaded go to menu>utilities>system information to check that all files were accepted.
Go to menu>option>parental lock>OK>enter 0000(default)>turn off install lock & parental lock>exit
Go to menu>accessory>key works>OK. Turn off all autorolls & emu>exit
Exit & go to RS232 mode>select type: dongle>network>ip setup>auto>apply. You should see an ip address appear(192.168.x.x). If you're not getting an ip then perhaps your router/gateway settings need to be adjusted. Like the firewall is set too high, or some port is blocked.
Exit>exit>select channel 239 & press the green button to populate the epg.
Wait for picture to come in. Enjoy.
Like I said I don't have access to a nano 2, but the procedure is similar.
Hope this helps.