Welcome to TBN. It,s a great site.
I have a 455, and I,m assuming your set-up is very close to mine.
This is what I do, hope it helps.
Before starting to remove the mower, with the tractor running, lift it as high as you can with your hieght adjuster.
Then turn all 4 wheels 90 degrees, and lock them in place, and lower the mower down as low as it will go.
Before shutting off tractor, turn the steering wheel to the right as far as it will go.
Release the front mower support and move it out of the way.
Remove the 4 pins that lock in the mower support arms near the back of the mower, and lower the arms gently onto the mower.
Pull the mower towards the front of the front of the tractor, and release the driveshaft, and place it on top of the mower at a 90 * angle.
Then start up the tractor, and lift the mower control as high as you can to get the lift brackets out of the way.
Shut off tractor, and roll the mower out the left side of the tractor.
How long have you had your tractor ? I find it gets easier, the more you do it. The mower is heavy, but it works great.
I live near Prescott, Ontario, in Canada. What part of Canada are you from ?