My Buddy has a 12 Gal Sears oil compressor. I think it is 1 or 1.5 hp that is fairly new. He wants to change the oil since it sits in a garage that has heavy condensation. Was over there last night and there does not seem to be a drain plug just a fill plug. His owners manual states to change after first 50 hrs then every 100. I agree he should do it frequently because of its location but we were reluctant to tip it over to get the oil out. I guess that is the only option?? The manual tells you to change it but there is no mention of the procedure. I know it takes 3 ounces and there is a bubble window that shows the level. Do you just tip it?