You can grip edit the cutting plane that defines a model documentation section view just like how you grip edit a polyline. 
Note: Model documentation is available only on 64-bit systems. 
- Verify that the GRIPS system variable is set to 3. 
  
- In the drawing view containing the section line, click the section line. Grips appear. 
  
- To reposition a grip, drag the grip. 
	 Tip: If the section line is constrained, the degrees of freedom allowed for dragging may be restricted. Tap SHIFT while dragging to relax the constraints. 
	  
- To add a line segment: 
	 - Move the cursor over the grip you want to insert the segment at. A menu displays. 
		
- Click Add Segment. 
		
- Click in the drawing area to indicate the end point of the line segment. 
		
 
- To add a vertex: 
	 - Move the cursor over a vertex. A menu displays. 
		
- Click Add Vertex. 
		
- Click in the position to add the vertex. 
		
 
- To remove a vertex: 
	 - Move the cursor over the vertex to delete. A menu displays. 
		
- Click Delete Vertex.