I decided to have the foot controller replaced on mine and my husband did it, then I found the instructions on line. Sew-Classic.com has step by step instructions. After that went so well, we replaced the power cord too. The parts were very inexpensive. They will also wire the foot controller for a small fee, so you don't have to do it yourself.
Look at their website and you will come away impressed. Did I mention the prices are very good?