To Remove All Pen Maps from a Pen Table

Select File > Print > Print.
The Print dialog opens.
Select Resymbolization > Attach Pen Table to attach a pen table.
In the Print dialog, do one of the following:

Select Resymbolization > Edit Pen Table.

or
Click the Resymbolization icon, and then click the pen table Edit icon.

The Modify Pen Table dialog opens.
Click the Map Pen Colors button.
The Pen Table - Map Design Colors to Output Pen Symbology dialog opens.
From the Edit menu, select Clear All Pen Maps.
Click Yes to clear all pen maps.
Click OK.