• Open the Site definition folder. If you use default Site definition, STS, then open the folder from the following location. “C:\program files\common files\Microsoft Shared\web server extensions\60\template\1033\STS

Note: Modifying the default files is not supported by Microsoft. Microsoft recommends using custom Site Definition.

• Open the List Definition folder. If you use default list definition for document library, then open the “DOCLIB” folder in the LISTS folder
  Open the “SCHEMA.XML” file in notepad or visual studio· Modify the LIST node by adding the EventSingAssembly, EventSinkClass, and
  EventSinkData

<List xmlns:ows="Microsoft SharePoint" Name="CustomDocuments" Title="Custom Shared Documents" Direction="0" Url="Custom Shared Documents" BaseType="1" EventSinkAssembly="TestEventHandler, Version=1.0.0.0, Culture=Neutral, PublicKeyToken=614ce6399d917f80" EventSinkClass="TestEventHandler.MyEventHandler" EventSinkData = "">

Note:Here I hardcoded the EventSinkAssembly for sample. Could you please change it according to your component.

• Restart IIS.

After configuring the details, if you create new document library based on the list definition, then the document library event handler will be automatically
configured.