Put some long planks under the rear end since you can get it lifted up. Put it back down on them.
Now, place your loader bucket in the full dump position, cutting edge down and back a little toward the front of the tractor.
As you engage the reverse, curl the bucket back to help push along with the pull of the tires.
I have yet to get stuck to where that won't get me out, and I've been all the way to the platform on my CK20. I actually have never even needed the boards under the rears.
If it looks like you could get out by going forward, do the same with the rears as above, but use the loader bucket the opposite way, starting with the bucket up, and use the power dump to pull you foward while you hit the forward gears.
You have less clearance on yours than I do on mine, do I'm not sure if this will work for you, but always has for me.
John