I have a bush that I want to remove from its pot, I have let it dry o

Depends on how big the pot is and what its made of... If its manageable you can turn it upside down rest it between 2 benches or some support and tap the pot all around to loosen it, use a large knife to loosen it around the sides. If the pot is plastic, and you don't mind losing it. You can cut it off and release the root ball of the Bush

Gently go around the soil with a knife to losen the edges

Go around the inside with a spade to loosen up .turn pot over and shake pot .if it is plastic you can cut the pot .

I think its easier when the plant is wet, sometimes you need to cut the pot.

I have had annual hanging plants that resisted coming out because the pot had that inner shelf in the bottom and the roots grew through it and I couldn't get it out until that shelf came out. I reuse my hanging pots to put strawberry plants in. I have also run into this with some houseplants that I was repotting into bigger pots. Does your pot perhaps have this?

turn the pot on its side, gently press down on the sides and roll pot around, making sure you touch all sides. This should help loosen the outside side.

I agree. Try soaking the plant and then turn the pot on its side and hot the sides to loosen it up.