Sewtoo

Hi I am hoping that someone out there has experience with threading up the Singer 111 w 155 ! And that person would be willing to explain to me how to do it. Years ago I hired a mechanic to come to my home to look at my machine and he said that it was fine, I just had it threaded incorrectly. He threaded well, and it was fine. I always changed thread by lifting the foot and pulling new thread through. Couple of years later, I broke the thread, pulling it through and had to rethread. Couldn't get it right. I bought a reprint of the manual and couldn't figure out the threading. I have tried many times to rethread and it always breaks when I sew. The mechanic was quite old and has since passed away. I really want to use the machine again! Can someone help?