Drupal6: let the user choose their password

I need to let the user enter their password开发者_JS百科 in the user/register process.

I've seen that Drupal generates a random password, but I need to let them enter a text field with their password: How can I do this without modifying Drupal core modules?

http://drupal.org/project/logintoboggan

Or:

http://drupal.org/project/user_registrationpassword (was created specific for this goal)