Delete custom un-used fields from a Managed Solution

According to the two following blogs it is possible to delete custom unused fields from a Managed Solution.

However, in both XML editing is required and this if I understand correct is unsupported by MS.

Is there any way to accomplish the same in a supported way?

blogs.msdn.com/.../deleting-things-from-a-deployed-crm-2011-managed-solution-package.aspx
mscrm-njl.blogspot.pt/.../how-to-delete-old-component-from-your.html;