adapt 2.4 Ghz modem to 5Ghz

I have a wireless (Wi-Fi) modem that has a 2.4Ghz radio that I need to convert to 5Ghz Wi-Fi. I have attached a picture of what the existsing hardware looks like. A couple of points to be aware of at the outset are: The volumes will not be high for this project so I will only be looking at 5-10 units initially. The device will need to have the same interface (6 pin Tyco) connections as the unit attached. I can supply the existing radio for testing if required. The 5GHZ modem needs to connect directly to an existing device and be able to have security settings adjusted.