How do you change the oil in a craftsman ride on mower?

There is a pipe with a plug on it that comes out of the engine near the bottom. Typically it will come out past the frame of the mower. Just get a pan to drain the oil into and sit it directly under that pipe. Remove the plug and let the oil drain. Depending on the model of the engine there may be a filter also. It looks just like a filter for a car. If it has one remove it at this time also. Once the oil stops draining just replace the plug, install a new filter, if applicable, and fill the engine with the recommended oil. If it has a filter you will need to check the oil again after you run it for a couple minutes.