Pull the main line out, so the spoil is moving freely. Do this until the spoil of line is tight with no loose line.

Repeat steps 4 and 5 for any remaining knots. Another knot may be present after you untangle the first one and start pulling the line out of the spoil. You will notice this when the spoil stops rotating again, and one or more loops are providing tension around the main line just like the initial knot was previously doing.