How do I rewind a double line weed eater

Hi,
Curved or straight shaft? Brand? Generally use your point of reference as the part that touches the ground. Lock the lines, could be a loop or receiver holes or other. Wind the line counter-clockwise for curved shaft and clockwise for straight shaft. Remember that point of reference I used as the operational direction is just the opposite of what I said. I told you the bottom and that is upside-down. If the spool happens to have two holes the line slide in the slide them in and wind the opposite direction that they slant. If it is auto-load, then there should be triangular arrows on the spool and body. Line them up, feed in the line until you feel resistance, then about a half inch further and wind in the direction it freely turns. See why the questions at thebeginning?
Peace,
Clarke