How do I upgrade from 3.x to 4.x?

Heh, well this points out a rather obvious deficiency in our README.txt documentation, which hasn't been updated for 4.x yet. Regardless, the approach is identical to upgrading any other module.

I've updated the text in README.txt to include the following. Is anything unclear?

Note that you must be running the latest 3.x version of Webform (for either
Drupal 6 or Drupal 7) before upgrading to Webform 4.x.

If you have contributed modules, custom modules, or theming on your Webforms,
please read over the documentation for upgrading your code for Webform 4.x at
https://drupal.org/node/1609324.

1. MAKE A DATABASE BACKUP. Upgrading to Webform 4.x makes a signficant number of
   database changes. If you encounter an error and need to downgrade, you must
   restore the previous database. You can make a database backup with your
   hosting provider, using the Backup and Migrate module, or from the command
   line.

2. Copy the entire webform directory the Drupal modules directory, replacing the
   old copy of Webform. DO NOT KEEP THE OLD COPY in the same directory or
   anywhere Drupal could possibily find it. Delete it from the server.

3. Login as an administrative user or change the $update_free_access in
   update.php to TRUE.

4. Run update.php (at http://www.example.com/update.php).

This was committed to 7.x-4.x in 6889662.

Committed to 8.x-4.x in e33c8e7 (to keep the branches in sync as much as possible atm).

The updated README makes much more sense, so marking as Fixed. @jhinxed feel free to re-open if you think it still needs work.

Hello!

Before I do number 2 above, should I still disable Webform 7.x-3.27 and uninstall it, or should I not take these steps, so I don't lose the form I've already created?

Thanks!