These features are out of box for BizTalk, so you have to run below scripts from the below location.
C:\Program Files (x86)\Microsoft BizTalk Server 2010\SDK\Utilities\Schema Generator
InstallDTD
InstallWFX
Also copy below assemblies from above location into the schema editor extensions folder.
Microsoft.BizTalk.DTDToXSDGenerator
Microsoft.BizTalk.WFXToXSDGenerator.dll
C:\Program Files (x86)\Microsoft BizTalk Server 2010\Developer Tools\Schema Editor Extensions
-Good Luck
