Comment Spam Pack - installation folder

Hello guys,

I have a problem with the installation folder. The guide on your website suggests:

To install:

1. Download the plugin file.

2. Unzip the file into a folder on your hard drive.

3. Upload /comment-spam-pack/ folder to /wp-content/plugins/ folder on your site.

The plugin developer suggests the following, I quote from the install.txt file in the plugin zip file:

Plugin Name: Comment Spam Pack
Author: Andrew Billits & Ulrich Sossou

Files:
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All files goes in /wp-content/mu-plugins

Instructions:
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1) Download the plugin zip
2) Unzip comment-spam-pack-1.zip from within the plugin zip
3) Upload the contents on 'Comment spam pack' to wp-content/mu-plugins/
(NB, do not upload the folder itself, just the contents)

To edit the captcha words:
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1) Open custom_anti_spam.php
2) Scroll to line 40
3) Edit / add words as appropriate

90494-1363030862

Please advise where to install the plugin. Thank you for your support.