In your EditDataFormTemplateSpec you will make the following changes to make the fields read only. 

Sample for text Box:
<common:FormField FieldID="DESCRIPTION" Caption="Description" DataType="String" ReadOnly="true"/>

Sample for Drop Down:
<common:FormField FieldID="CATEGORYCODEID" Caption="Category" ReadOnly="true"> <common:CodeTable CodeTableName="WIDGETCATEGORYCODE"/>

After making these necessary changes the following steps need to take place.

1. Build the project.
2. Move your .dll to the vroot/bin directory on the server
3. Navigate to Administration => Application => Catalog Browser
4. Reload Package
5. Refresh Shell Navigation under the Tools Menu