following the email I received, i need to update my ACME client to use an alternative validation
method (HTTP-01, DNS-01 or TLS-ALPN-01) My current certbot version is 0.25. Can someone help me step by step please?
My domain is: www.karibbeancars.fr
My web server is (include version): raspberry pi
The operating system my web server runs on is (include version): Apache 2 / desbian 9 stretch
You might try certbot renew --dry-run before trying to upgrade. If the dry run works without an error, it shouldn’t be needed.
Thx for your answer Osiris but i have an error 
The following error was encountered:
[Errno 13] Permission denied: ‘/var/log/letsencrypt/.certbot.lock’
Either run as root, or set --config-dir, --work-dir, and --logs-dir to writeable paths.
That would suggest there's another instance of certbot running. Anything with ps aux | grep certbot?
If you're sure there's no certbot running, you can just remove the lock file, apparently some certbot instance left it there, perhaps when it crashed.
Or perhaps...
Hi Osiris,
i tried your command, here is the result :
pi 27840 0.0 0.0 4372 552 pts/0 S+ 19:15 0:00 grep --color=auto certbot
I believe @rg305’s observation is right: you should run the command as root (probably via sudo).
Instead of certbot renew --dry-run, you can run sudo certbot renew --dry-run (in order to find out whether your existing version will work without upgrading).
sorry for my misunderstanding, I think the command worked i have this message :
** DRY RUN: simulating 'certbot renew' close to cert expiry
** (The test certificates below have not been saved.)
Congratulations, all renewals succeeded. The following certs have been renewed:
/etc/letsencrypt/live/www.karibbeancars.fr/fullchain.pem (success)
** DRY RUN: simulating 'certbot renew' close to cert expiry
** (The test certificates above have not been saved.)
Great, this suggests that following the end of TLS-SNI-01 support, your existing version of Certbot should be able to switch over successfully to using the HTTP-01 method, without further changes.
Yesssssssssss, thx for that great news
Thx to everybody for the help 