How to replace a kitchen sink drain?

Question:

Answers:
There are several components to a sink drain, the outlet is the base of the sink, attached by a large nut immediately under the waste aperture in the sink, the trap is below this and will be screwed onto the last bit, it will connect to the waste pipe with another nut assembly, undo both nuts to seperate them and it will be full of water(keep it upright and don't empty it into the sink), the trap etc should be 11/2" unless you are calling the bathroom basin a sink in which case it will be 11/4". Hope this helps.