Yes, I have taken off the rubrail. Just remove the screws and be very careful not to let the rail bind or kink. If you bend it, it's no good. You may have to use some replacement screws that are longer to replace the rubrail but not too long. Use plenty of caulk or 5200 on the hull/deck joint for leaking.
To keep the rail from bending, as I unscrewed it from the boat I tied a string to it and then to a lifeline to hold it in place and did that as I removed the rail along the boat.