This tutorial shows the whole process of downloading WordPress plugin from CodeCanyon, unpacking it and installing in the WordPress website. Also, you will see how to update existing plugin when new version is released.
Step 1: Download plugin from CodeCanyon
Once you purchased WordPress plugin, you need to download it. Open the Downloads panel in your CodeCanyon account, and you will see something like this:
Click on the Download button, and save the file to disk.
Step 2: Install The Plugin
ZIP file you have download contains plugin, and you can install it directly from WordPress -> Plugins -> Add New panel, just select the ZIP you download, and it will install correctly. Inside the ZIP file, you have one folder where the plugin is, and inside it is DOCS folder with documentation.
Step 3: Upload the plugin folder to WordPress website using FTP
Common method to install the plugin is to upload it via FTP to your website. To do this, we are going to use FileZilla, a great and free application available for Windows and Mac OS. Very important thing here is to know what to upload. ZIP file you download you need to unpack first. It will give you one directory named as a plugin. In the example here, that is directory/folder named: smart-cleanup-tools.
This directory, needs to be copied to your website in the wp-content/plugins directory. To do this, connect using FileZilla to your website FTP server (you can get this information from your hosting account). Once connected, browse the FTP remote site, until you get in the plugins folder:
On the Local side (left by default), browse to the folder where you have unpacked the plugin. Now, if the remote plugins folder is opened on the right side, simply drag the smart-cleanup-tools folder (or whatever plugin you downloaded folder) into the right side, and drop to start upload process. You will see the progress bellow, and once it is done, you can close FileZilla and get to last step.
Step 4: Activate plugin through WordPress
Now that plugin is uploaded, you need to log into your WordPress website, and open the Plugins panel on the Administration side.
In the list you see Smart Cleanup Tools plugin. Simply click on Activate link for it, and it will activate.
Bonus: Upgrading existing plugin
Since I tend to update my plugins often, to fix bugs and add new things, you will need to upgrade plugin on your website from time to time. Process is pretty much the same as with installing plugin from scratch. Download the new version (CodeCanyon always let you download last released version of the plugin), unpack it. When it comes to upload, when you drag and drop folder into remote plugins folder that already contains the old plugin version, you will be asked what to do with existing files, and dialog will look like this:
As on this dialog, select Overwrite option, and check Always use this action below. All existing files will be replaced, and plugin will be updated.
Also, you can safely delete old plugin from remote plugins folder, and than upload new version of the plugin.
Notice: Should I deactivate plugin before upgrading it?
To be honest, I never do that. With older versions of the WordPress (before 2.7), this was useful step, but not anymore. There should be no problems with upgrading active plugin. But, if you want to be extra safe, please deactivate plugins from WordPress Plugins panel before upgrade, and activate it back once it is done.