To Remove an Existing Knot Point from a B-spline Curve

Select the Edit Knots tool ( Modeling > Curves > Modify Curves ).
Select the Remove Knots icon.
Select the B-spline curve.
Graphics display the existing knot points.
Select the knot to be removed.
Enter a data point to accept the change.
(Optional) Select more knots to remove and accept by entering data point.

Removing existing Knot Point. Method = Single, Control Points = On