If you ever need to modify an ASA startup config for example if you are changing internet provider and need your wife to just reboot the device so it works with your new ISP’s PPPoE settings, here’s what you need to do.
Using ASDM is quite straightforward.
First download the configuration files
ASDM > Tools > Backup Configurations:
Leave “Backup All” checked
Click “Browse Local…” (name it and save it to your desktop)
Extract and edit the startup-config
Extract the zip and edit the startup-config.cfg file with your favorite editor.
Just in case do not delete your original backup zip file.
Copy your edited startup-config from your PC to the ASA flash
ASDM > File Management… > File Transfer > Between Local PC and Flash…
Upload your new startup-config.cfg to the root of disk0:
Copy the startup-config from ASA flash to NVRAM
Type the following at the actual CLI or in the ASDM CLI:
copy /noconfirm disk0:/startup-config.cfg startup-config
Enter or send
Now check the startup config is different to the running config. Job done. Now if you are rebooting via the ASDM you will need to “Reload without saving the running configuration” and schedule the reload. Of course you could also just your wife/daughter/son/partner to cut the power and bring it online again.
Your ASA will now reboot with the required config.