After clicking the "Check out with PayPal" button you will receive an email with a download link. The download link is valid for 60 minutes. In addition you will be redirected to a page on this site where you can download the add-on directly. Download the file to your local desktop machine. Next open your browser and navigate to your ReadyNAS' web interface (Frontview).
Beginning with RAIDiator 4.2.16 Netgear introduced a new "Add-Ons" menu. First click on the small white triangle to fold out the menu. Next select"Add new" to get to the upload dialogue.
The rest of the procedure floows closely the procedure on the Sparc ReadyNAS: Click on the "Choose File" button, select the add-on file from the folder on your hard drive where you saved it and finally click the "Upload and verify image.." button. There will be a popup message that you can safely dismiss by clicking the "Ok" button. Once the upload is verified a status screen with additional information appears. Click the "Perform System Upgrade" button. If all went well a popup message will appear after a while, saying "Add-on installed successfully".
Click on the "Configure" button in the upper left corner of the Dashboard. This will bring you to the main configuration interface of your ReadyNAS. Here you have to select the "Add-Ons" button in the menu bar to get to the add-ons overview. Initially you will be taken to the "Available" overview pane. If you want to you can switch to the "Installed" pane, but that's not necessary to install an add-on.
Just click on the "Add Add-on" button that's hidden away to the complete right of the "Available/Installed" selection panel (the one marked with a red border in the picture). After clicking that, a popup window opens where you can choose the add-on to upload to your ReadyNAS.
Once the upload is finished and the add-on was verified a new popup window with additional information about the add-on appears. Click the "Install" button. The ReadyNAS will now start to install the add-on. If all went well a popup message will appear after a while, saying "Add-on installed successfully" and the add-on will be listed on the "Installed" pane.
Note: Due to a problem with the current add-on system on ARM ReadyNAS devices the installation of add-ons that are quite big in size or take a long time to install will result in an error message saying "Failed to install add-on". This is not the case! In truth the add-on just hasn't finished installing. If you receive this message when installing an add-on, please wait another couple of minutes and check the "Installed" pane. If the add-on shows up there, all should be well.
Before installing ANY other add-on it is highly advisable to install Netgear's EnableRootSSH add-on ([Intel version] - [ARM version] - [Sparc version]). Although the add-ons on this site are tested before they are released there's no way to test every possible setup. If anything goes wrong, SSH access may be the only way to correct any problems you may encounter. So do yourself a favor and use the EnableRootSSH add-on at least while test driving a new add-on.