Some gotchas while Renewing two Digital Signatures.......... mybe of interest.
System Windows 10 22H2
Firefox 118.0.1 (64-bit)
Google Chrome 117.0.5938.132 (64-bit)
as it will be four years since you got it ........the instructions are on the site
https://www.sede.fnmt.gob.es/certificad ... ca/renovar
Download and install the latest FNMT-RCM and Autofirma Software
Some popup boxes will Hide behind the Browser window.............

when you have completed one and Downloaded the Certificate you may have another to complete.........currently my version of Firfox dosen't ask which Certificate to use and stays locked in with the first Certificate.
So over to Chrome and do the second one there as the Default allows one to choose the Certificate.
You may just sail through on your system ................the above might help you renew without loosing to much sleep.........
Check out the new Digital Cerificates then.............
NB: Make backup copies on different media/systems by using the Export/Backup Option depending on Browser.
Interesting point with the "new renewal software"........... all the supported Browsers that you may have on your system e.g. (Firefox, Chrome, Edge)
will get updated with the New Digital Signatures without having to use the Import option.