A simple block and tackle will lift it...
You need to lift 450 lbs, so if you get two blocks with two pulleys in each you'd have a 4 to 1 reduction so 450 / 4 = 112.5 lbs of pull. If you weigh more then 112.5 lbs then you can pull up this load with your own weight.
If you want to make it easier, get one block with three pulleys in it and now you have 5 to 1 or 90 lbs of pull.
To reduce the needed pull even more you could create a small winch to wind up the rope.
We saw a thing like this in a workshop at the Shaker village:



This shows a shaft with a wheel on one end. The rope would wind around the shaft and the wheel can be turned by hand or with another rope.
If this shaft is 8" in diameter and the wheel is 48" in diameter you have another reduction in effort of 6 to 1. So 90 / 6 = 15 lbs. So now only 15 lbs of pressure will lift 450 lbs of timber.
(Friction factors may add a few pounds to the load and other weights).

Jim Rogers