how to insert and remove Xml document fragment between nodes?

how to insert and remove Xml document fragment between nodes.I want to add and remove xml fragment inside particular tag.

<project> 
<ItemGroup>
<Content Include="App_LocalResources" />
  </ItemGroup>
<ItemGroup>
<EmbeddedResource Include="lice.pccx" />
</ItemGroup>
<Import Project="$(MSBuildBinPath)" />
<Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v10.0" />
  </project>  I want to insert    
   <!--<EmbeddedResource Include=licenses.licx />--> 
    xml Fragment inside 
  <ItemGroup>
    <EmbeddedResource Include="lice.pccx" />
   </ItemGroup> And after that I want to remove <EmbeddedResource Include="lice.pccx" /> xml element from xml document.