If it's a 2001A, just find someone local to downgrade it for you. Usually anywhere between 45-70.
It's not worth getting an ODE anyways. 4.55 to 4.65 had massive problems with ODE's being blocked and the only workaround was a goofy swap disc method. Now the 4.65 work around is a swap disc for the swap disc and requires newer hardware. Definitely not worth the investment in an ODE device.
Downgrade the console and load up CFW. Infinitely better anyways.
To answer your question, the swap disc method was basically to put in a burned CD made from Cobra tools that would authenticate in the PS3, then require ejecting and put in your burned disc (or ISO) that you wanted to play. The 4.65 method requires 2 swap discs + original/ISO.
You'll be much happier with CFW and can do so much more for half the cost.
Doesn't the swap disc need to be a BD-R?
Does anyone know if there is a downgrade method supported under ODE to get the best of both worlds? An E3 kit (or a downgrade service) ends up being about the same as the 3k3y (or somewhat cheaper than the Cobra ODE).
I'm in the same boat as the OP so I'm wondering what to do myself.