sv_map mapname
in f2 to change the mapautoexec_server.cfg
3. set sv_rcon_password "YOUR_PASSWORD_HERE"
to something simple you can type fast and remember
4. set sv_map "YOUR_MAP_NAME_HERE"
to any map name that you're saving to. So it will load this map automatically when starting the server. I'd recommend using any buffer-name, so you can save new map with that name, run the server, try it. If you don't like it at all - just rewrite the file with a new map on other day. If it's ok for you - continue mapping and save it with real name after.
5. use reload
command in F2 (rcon console) to reload the map if you made any changes in editor (remember to save changes in editor before doing reload) (edited)