The two most probable reasons for a washing machine failing to drain water from its drum are a blockage at some point in the drainage system or failure of the washer's pumping mechanism.
Removing The Water
Before you do anything to remedy the fault, you must drain the water from the machine and remove the clothing. How you do this will depend on whether your washing machine has a washing pump filter and a filter drain hose or not. Your washing machine user manual will identify the location of these features.
If your machine has a pump filter and a filter drain hose, open the pump filter flap and pull the small drain hose forward. Have a large basin on hand to catch the water. The water should then be drained into the basin.
Machines With No Pump Filter
If your machine has no pump filter and small drain hose, you will have to access the hose through which washing and rinsing water exits at the rear of the machine.
This hose should be separated from its wastewater pipe and lowered into a bucket or large basin to allow water to drain out of the washer.
Spin the Clothing
Once the water is drained, the machine should be able to spin the clothing in the drum. To do this you'll need to start with a completely empty bucket or basin, with spares close at hand. After this you'll be able to open the door and remove the items.