If you read your owners manual it will say drain gas tank and run mower till the carburetor is empty. Then it will be ok to tip the mower till you get all the oil out. It would be so much easier if the manufacture would just charge another couple of dollars and install a drain plug. I did see some time back that that B&S was making a small mower engine with a lifetime oil in it. I don't know how that ever worked out?