values associated with features on a map are contained in the layer's table... open it and change it there. If working in arcmap, get into an edit session. Finish with geometry edits... then do attribute edits,
FYI... your question title is really the body of the question...
Could you not just change the values in attribute table? You should edit the vertices of the polygons only if you want their geometry to be changed.
No. i'm trying to overlay the green layer with the brown layer. when you click on a point in the area above ( the green with white stripes or the solid green), the marker represents the value for the two different layers (overlay). however, the light brown square only contains the value for one layer- the light brown. simply changing the values in the attribute table doesn't do it.
Are you trying to do a union of the two layers (Union—Help | ArcGIS Desktop ) and concatenate the values (Calculate Field examples—Help | ArcGIS Desktop ) of two fields from the different layers?