How to edit a released document via nash?

I have got some documents in released state and therefore cant edit them anymore. To not manually revise, update and release 50 documents again, i would like to update / edit a property of them via nash / batch import tool. Logged in as root, still no access is given.

<AML>
<Item type='Document' action='edit' where="[item_number]= 'R940-00002'">
    <rg_type_acronym>CSL</rg_type_acronym>
</Item>
</AML>

===>

-<SOAP-ENV:Envelope>
-<SOAP-ENV:Body>
-<SOAP-ENV:Fault>
  < faultcode > SOAP-ENV:Server.ItemCannotBeLockedException </ faultcode >
  < faultstring > The Document with ID 005B9D7B7F5D4F8FACB70EB97E8D883E you are trying to edit is in a Not Lockable lifecycle state. </ faultstring >
-<detail>
  < af:legacy_detail > The Document with ID 005B9D7B7F5D4F8FACB70EB97E8D883E you are trying to edit is in a Not Lockable lifecycle state. </ af:legacy_detail >
  < af:exception message =" The Document with ID 005B9D7B7F5D4F8FACB70EB97E8D883E you are trying to edit is in a Not Lockable lifecycle state. " type =" Aras.Server.Core.ItemCannotBeLockedException " />
  < af:item type =" Document " id =" 005B9D7B7F5D4F8FACB70EB97E8D883E " />
 </detail>
 </SOAP-ENV:Fault>
 </SOAP-ENV:Body>
 </SOAP-ENV:Envelope>
-------- another approach ---------
I successfully tried with some other code to reset lifecycle state from "released" to "in work" state (a corresponding path must be available in the lc map before).
Then i could use another script to update it and use a third script to promote it again. Might most probably work, but I would prefer to have a direct way to do such an update.
Is there any possible way doing this by nash directly on one step most only?
Many thanks
Kind regards
Marcel