Use the Shrink To Seeds tool
in the Parcel group in the Tools gallery to modify the line geometry of selected parcels.
The Shrink To Seeds tool replaces selected parcel polygons with parcel seeds and leaves the original parcel lines in place for editing and modification. The attributes of the original polygons are copied to the parcel seeds. After the line geometry is modified, updated parcels can be built from the updated lines enclosing the seeds. The attributes of the seeds are transferred to the newly built parcels.
Build parcels
To build parcels from the updated line geometry and seeds, you can use the Build Active tool 
or the Build Extent tool 
in the Construct group on the Records tab.
The Build Active tool builds parcels in the active record. If you create new lines, the record of the original parcels must be set as active in the map and the lines must be assigned to the active record before building parcels. You can also set the record of the original parcels as active in the map before you start modifying or creating lines.
The Build Extent tool builds parcels in the map extent. If a seed is enclosed by lines associated with different records or no record, the parcel is not built. When you create lines, the record of the original parcels must be set as active in the map and the lines must be assigned to the active record before building parcels.
To modify and update parcel line geometry, follow these steps:
- Select the parcels you want to modify, and
in the Parcel group, in the Tools gallery, click Shrink To Seeds .
- If you are creating new lines set the record of the original parcels as active in the map.
Tip:
Select the parcels you are modifying, click the Menu button
on the records heads-up-display and click Activate Record of Selected Feature. - Use editing tools such as the Traverse tool
and the Two-Point Line tool 
to create lines. Use the editing tools in the Reshape group in the Modify Features pane to modify existing line geometry.Tip:
The Replace Geometry tool preserves the attributes of the original line feature and thus preserves the line's association with the parcel record (Created By Record field). - Build parcels from the updated parcel lines and seeds.