Heather,
DON'T REMOVE THE HEADWhat you have to do is get two pieces of nylon(2mm) about one & half metres long.
Then on the head you line up the two triangles.
Then you push the nylon into each hole(outside of head) and it should come up near the bump button. You put the end into the small hole and then pull the nylon.
Once you have located both bits of nylon in the head you then wind the head up till the nylon only has about three inches left.
You are ready to use the machine.
Regards,
Bruce