diff --git a/README.md b/README.md
index 4946464..99cb8f2 100644
--- a/README.md
+++ b/README.md
@@ -125,7 +125,14 @@ sudo cp /usr/local/etc/letsencrypt/live/www.example.com/privkey.pem .
 chmod 400 cert.pem privkey.pem
 ```
 
-Renews can be done running `certbot renew` (untested!).
+Renews can be done as follows:
+
+```sh
+sudo service pf stop   # shutdown firewall
+sudo certbot renew
+```
+
+and then copy the `cert.pem` and `privkey.pem` files to `aprendizations/certs` directory. Change permissions as appropriate.
 
 
 ### Testing
--
libgit2 0.21.2