It's pretty straightforward. The switches and flashers have connectors under-field. Disconnect them and push them up through the holes in the field.
Then start taking the screws out and gently lift the ramp assembly to see where the next screw is holding it. Don't forget the two #1 Philips screws at the entrances. I think you have to remove the metal exit rails first.
If the top screws aren't accessible, rotate the field up and reach in and down to remove them. You don't have to pull the field.
Take notes of what comes off first, and keep the hardware separate (an ice cube tray works good). Take a lot of pics if you're nervous.