One way to transfer the ion exchange media from one tank to another tank:
Siphon water out of the tank with siphon hose stuck all the way down into the center pipe filter basket.
The tank will then weigh a lot less (water weighs over 8 lbs per gallon) and become more manageable.
Don't just dump the tank upside down as the media will tend to jell and plug the neck and won't "flow" even if jiggled.
Lift/elevate the tank horizontally (it still will be somewhat heavy but a lot lighter than before).
Put a sterile/clean large trashcan below the neck of the tank.
With a hose (or pitchers of water) get some water back into the elevated tank to create a slurry.
Tilt the tank and pour contents into the trashcan. Repeat this a couple of times. The key
is the slurry.
Bail most of the water out of the trashcan (the media resin settles quickly).
Scoop and transfer the media (with a plastic water pitcher or similar) into the new tank.
Enjoy your new tank.