First create an back-up (important)
under server management -> tools & settings -> -> tools & resources -> back-up manager
Left top, click "back-up"
Make a incremental back up, add to the comments "Incremental manual back-up updates (date) (yourname)"
Go to -> Server management -> Wordpress on the top bar click on "Updates"
On the new window click "Check Updates"
Make sure to deselect Jadrimex we do not want to update this domain.
Press update.
Manuel update plugins:
Go to -> Server management -> Wordpress, open the site and press the log in button.
on the left side go to the plugins, select the plugin you want to update.
press update.
Check if the websites are still functional, go by them one by one.
You'll know when it has issue's.
If everything is looking good, you're done.
If it is wrong, you need to roll back the back-up.