My friend has this old long arm machine that we have been trying to get adjusted. Neither one of us know what we are doing. She bought it from someone else and didn't ask any questions. She said we had to change the oil in it. We had to literally pick the machine up off it's base and pour the oil in to the fill line. Are all of them like that or is there an easier way. Her machine was very heavy and it took both of us to do it? And how often does that have to be done under normal use?