I have a Kenmore portable model 110 84870800 how can I change water pump?

My washer wont drain the water! I think it's the water pump but I'm not to sure. Also if someone can help me with step to step instructions that can be helpfull to me...PLEASE! Damsel in distress!I have a Kenmore portable model 110 84870800 how can I change water pump?If your washer is not draining it the washer thats the problem!