How to change meta tags in Drupal?

I am using some old version of drupal. I would like to c开发者_如何学JAVAhange meta keywords and descriptions however they are not changeable from admin interface. I guess they cannot be changed by manually editing the files on the server. So, the question is: how to edit these meta tags? I am using Drupal 5 or 4(?). Any advice appreciated.

nodewords, seems the D5 version is still available (while not maintaned anymore)