I have a very simple rule with Event "Before saving content" and Elements "Content is of type (page)" and would like the action to be something similar to "Change node author to UID X", which would be the UID I want.

I can't seem to be able to achieve that with the actions exposed. To test my rule I've been trying to display a message on the site when triggering the rule and it works just fine.

Any idea how to do that without having to write code?

I have a very simple rule with Event "Before saving content" and Elements "Content is of type (page)" and would like the action to be something similar to "Change node author to UID X", which would be the UID I want.

I can't seem to be able to achieve that with the actions exposed. To test my rule I've been trying to display a message on the site when triggering the rule and it works just fine.

Any idea how to do that without having to write code?

This is on Drupal 7 (latest) with latest stable Rules version.