You can modify a gtol by changing the value of an individual material condition symbol, or by adding, removing, or replacing a datum reference.
When you click Insert > Geometric Tolerance, the Geometric Tolerance dialog box opens.
Click Make Target on the GEOM TOL menu.
Select a "set" reference datum in the drawing that the datum targets are defining. You can also select draft datum planes and axes.
Select one of the following from the TARGET menu:
Simple—Contains the name of the referenced datum in the lower half of the datum target symbol.
Diameter—Selects a dimension for each datum point, and displays it in the top half of the datum target symbol.
The GET DTM PNT menu appears.
Click Select Point.
Pick a datum point in the drawing or click Create Point and create a point as needed.
Pick the location for the target.
About Geometric Tolerances