Change invitation message on active Survey

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I need to change a name on the invitation message from an active Survey. Due to the history on the Survey we like to keep the current survey and not create a copy.

I think found a solution, but are not 100% sure this is working.

I'll open the Survey and go to the Delivery tab. Click on Suspend.
Than open the invitation Message which is still not editable.
I copy all what is in this HTML message and click on the Tasks -> New Document and past all back again and change the name. 
Than click on the Text and do the same.