Go to iTunes Store and download iPublishCentral reader for iPad 

OR

Open the link below on Safari on your iPad, download and install the app :

https://itunes.apple.com/us/app/ioffline/id510322929?mt=8

To download the file from any online source directly to the reader.

Once you have the reader downloaded and installed on your device.

You can download the ePub file directly from any Online Source.

Once downloaded, the file will open up giving you options (as indicated in the reference image below)

• Open in
• Open in iBooks(Default action)

Tap on  Open in and you will have a pop up showing you the options( as indicated in the reference image below)

Select iPublishCentral Reader and the Reader will open

The eBook will get downloaded and will appear on the "All Books" Tab.

Tap on it to read.

To transfer the file from your computer using iTunes

Step One

Download the ePub title and save it on your desktop

Step Two
Launch iTunes on your computer by clicking its icon in the dock/on the desktop/in the list of programs 


Step Three

Connect your iPad to the computer and select it from the list of devices on the left.

Step Four

Click to select the Apps tab

 Step Five

Select the Reader from the list

Click on Add and choose the file that you wish to open using the reader.

If you already have the reader open on your iPad , please quit it and open again.

Tap on the eBook to read(indicated as New )