deleting running-config on 891f router

[AndrewTCS]

I'm am pretty sure in the past I have deleted a running config with commands from the cli. Something like "erase running-config" but today I'm not seeing the option to erase the running-config, but only the startup-config.

Is there a way to delete the running-config? or do I need to delete the startup and then reload the router.

My goal is to put a new running config on there, then test its working, save and reload.

[Flavio Miranda]

@AndrewTCS 

 You can erase the startup-config and reload the router. 

   The running-config is the config on the Router´s RAM memory and the startup-config is on the ROM memory.  We make changes on the running-config but in order to keep the change we need to save indo startup-config.  In the same way, if we want to wipe out the config, we need to delete (erase) the startup-config. 

[Joseph W. Doherty]

Hmm, I very vaguely (???) recall being able to do that too.

However, it may be unnecessary if the platform supports the replace command.  See https://community.cisco.com/t5/networking-knowledge-base/using-the-configure-replace-command/ta-p/3115435. BTW, consider carefully the replacement file contents, which I believe don't need to be actual startup config.