SharepPoint 2010 Feature Upgrade Action rename field declarative way
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I'm looking into Sharepoint 2010 Feature upgrade framework and all over the net I'm seeing examples of how to upgrade a feature by adding a new field to a existing content type and this is done like this:

      <UpgradeActions>

    <VersionRange BeginVersion="0.0.0.0" EndVersion="0.9.9.9">

      <ApplyElementManifests>

        <ElementManifest Location="SomeFunctionality_Iteration2\Elements.xml" />

      </ApplyElementManifests>

      

      <AddContentTypeField ContentTypeId="0x010073f25e2ac37846bb8e884770fb7307c7"

          FieldId="{536DC46C-DC26-4DB0-A97C-7C21E4362A85}" PushDown="TRUE"/>

      <AddContentTypeField ContentTypeId="0x010073f25e2ac37846bb8e884770fb7307c7"

          FieldId="{4E7A6719-011A-47EA-B983-A4941D688CA6}" PushDown="TRUE"/>

 

What i don't understand is how would i perform an upgrade to a feature which would **rename**,**delete** or change any other property  a field declaratively from the content type the feature already deployed.

All over the net I'm seeing examples of how to add a Field, but how do i change properties of existing ones using Feature Versioning and Upgrading.

Thanks!