Once you have identified one or more knots and have the pliers lightly clinched upon them (one at a time), begin to provide tension to the knot by pulling it up or towards you.

This will allow for the knot to come out of the spoil.

The alternative to steps 3 and 4 is shown by the second and third pictures below. If you do not have needle nose pliers with you, it can be done by hand but will be more difficult.