You'll need new remotes. I had email offering 360 and got very quick response and delivery. Alternatively go into your account online and look for upgrade option there.
Have you tried pressing "Home" on remote? Option to upgrade to 360 is bottom of menu. Beware, you'll lose all recordings when upgrading. I put 360 stuff back in box but once you opt for 360 the system will upgrade automatically after 7 days. I didn't realise this so will be losing a load of stuff soon.