That's right.
In terms of the database, the installer will upgrade you gradually to the latest version so you only need to run that once.
However with the files and the structure of how they are organized you will need to follow the
steps for each upgrade.
What you need to do is download v1.3.5 and do the following..
So you need to do the following with v1.3.5:
- Enter your details in comments/includes/db/connect.php and upload it.
- Upload the comments/includes/language/ folder.
- Upload the comments/includes/emails/ folder.
- Upload the comments/agreement/ folder.
- Upload admin_tips.txt and detect_links.txt from comments/includes/words/
Add your signature to your emails (Settings -> Email)
Then on your server delete the following files and folders:
a) comments/includes/language/comments.php
b) comments/includes/language/database_errors.php
c) comments/includes/language/form.php
d) comments/includes/language/page.php
e) comments/includes/language/processor.php
f) comments/agreement/privacy_policy.html
g) comments/agreement/terms_and_conditions.html
h) comments/includes/emails/admin/
i) comments/includes/emails/user/