Hello,
Welcome to ChimeraX!  To use renumber, you need to get a new daily build of ChimeraX:

<https://urldefense.com/v3/__https://www.rbvi.ucsf.edu/chimerax/download.html*daily__;Iw!!PhOWcWs!2lryUSPfs2dT9AXnsTmPafxL6Z1IqB2A5rBjitnyHL143f1MxJBOlPqsNjjMaBVxoum5TV8h_iThvP8rU0BPCAE$ >

As shown in the "change log," renumber was added after the 1.4 release:

<https://urldefense.com/v3/__https://www.rbvi.ucsf.edu/trac/ChimeraX/wiki/ChangeLog__;!!PhOWcWs!2lryUSPfs2dT9AXnsTmPafxL6Z1IqB2A5rBjitnyHL143f1MxJBOlPqsNjjMaBVxoum5TV8h_iThvP8rHvUxMDE$ >

When you saw "renumber," you were probably looking at the User Guide on our website, which is always updated to the newest features.  If you use menu: Help... User Guide (instead of web search) it will show documentation that should match the features in your download.

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                      
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco


> On Jul 27, 2022, at 8:02 AM, Kwangjun Lee via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
>
> Hello,
>
> I am a new user of ChimeraX.
> I have tried to renumber AA but renumber is an unknown command.
> Is there any way that I renumber? For example, my current model starts C 1, I want to renumber it to C 20.
>
> Thanks for developing a great software.
>