Deploy & Configure Office Web Apps Server for SharePoint 2013 on Windows Server 2013

Step 1: Install prerequisite software for Office Web Apps Server:

1. Open the Windows PowerShell prompt as an administrator and run this command to install the required roles and services.

Add-WindowsFeature Web-Server,Web-Mgmt-Tools,Web-Mgmt-Console,Web-WebServer,Web-Common-Http,Web-Default-Doc,Web-Static-Content,Web-Performance,Web-Stat-Compression,Web-Dyn-Compression,Web-Security,Web-Filtering,Web-Windows-Auth,Web-App-Dev,Web-Net-Ext45,Web-Asp-Net45,Web-ISAPI-Ext,Web-ISAPI-Filter,Web-Includes,InkandHandwritingServices,NET-Framework-Features,NET-Framework-Core 

Step 2: Install Office Web Apps Server:

1. Download Office Web Apps Server from the http://www.microsoft.com/en-eg/download/details.aspx?id=35489
2. Open the .img file directly and run Setup.exe.
3. On the Read the Microsoft Software License Terms page, select I accept the terms of this agreement and click Continue.
4. On the Choose a file location page, select the folder where you want the Office Web Apps Server files to be installed (for example, C:\Program Files\Microsoft Office Web Apps) and select Install Now. If the folder you specified doesn’t exist, Setup creates it for you.
5. When Setup finishes installing Office Web Apps Server, choose Close.
6. Download and install the Office Web Apps Server update KB2810007.

Step 3: Install language packs for Office Web Apps Server:

1. Download the Office Web Apps Server Language Packs from the http://www.microsoft.com/en-eg/download/details.aspx?id=35490
2. Run WebAppsServerLP_en-us_x64.exe.
3. In the Office Web Apps Server Language Pack 2013 Wizard, on the Read the Microsoft Software License Terms page, select I accept the terms of this agreement and select Continue.
4. When Setup finishes installing Office Web Apps Server, choose Close.

Note: 

• To install language packs after the Office Web Apps Server farm is created, you must remove a server from the farm, install the language pack on it, and then add the server back to the farm.
• For a language pack to work correctly, you’ll need to install it on all servers in the farm.

Step 4: Deploy the Office Web Apps Server farm:

New-OfficeWebAppsFarm –InternalURL "http://servername" -AllowHttp 

Parameters–InternalURL is the name of the server that runs Office Web Apps Server, such as http://servername.
–AllowHttp configures the farm to use HTTP. 
–EditingEnabled enables editing in Office Web Apps when used with SharePoint 2013. This parameter isn't used by Lync Server 2013 or Exchange Server 2013 because those hosts don't support editing


Note

If Windows PowerShell doesn’t recognize the New-OfficeWebAppsFarm cmdlet when you runit, you may need to import the OfficeWebApps module. Use this command:
Import-Module -Name OfficeWebApps
Step 5: Open an elevated SharePoint 2013 Management Shell:

Right-click SharePoint 2013 Management Shell to display the app bar.
In the app bar, click Run as administrator.


Step 6: Create the binding between SharePoint 2013 and Office Web Apps Server:

Run the following command, where <WacServerName> is the fully qualified domain name (FQDN) of the URL that you set for the internal URL. This is the point of entry for Office Web Apps Server traffic. For this test environment, you need to specify the –AllowHTTP parameter to allow SharePoint 2013 to receive discovery information from the Office Web Apps Server farm by using HTTP. If you don’t specify –AllowHTTP, SharePoint 2013 will try to use HTTPS to communicate with the Office Web Apps Server farm, and this command won’t work.

New-SPWOPIBinding -ServerName <WacServerName> -AllowHTTP

Step 7: View the WOPI zones for the SharePoint bindings:

Office Web Apps Server uses zones to determine which URL (internal or external) and which protocol (HTTP or HTTPS) to use when it communicates with the host, in this case, SharePoint 2013. By default, SharePoint Server 2013 uses the internal-https zone. Run the following command to see what your current zone is.

Get-SPWOPIZone

Step 8: Change the WOPI zone to internal-http

If the result from Step 3 was internal-https, run the following command to change the zone to internal-http. You need to make this change because the zone of SharePoint 2013 must match the zone of the Office Web Apps Server farm.

Set-SPWOPIZone –zone “internal-http”

Verify that the new zone is internal-http by running Get-SPWOPIZone again. 

Step 9: Change the AllowOAuthOverHttp setting in SharePoint 2013 to True
To use Office Web Apps with SharePoint 2013 over HTTP in a test environment, you need to set AllowOAuthOverHttp to True. Otherwise Office Web Apps won’t work. You can check the current status by running the following example.
(Get-SPSecurityTokenServiceConfig).AllowOAuthOverHttp
$config = (Get-SPSecurityTokenServiceConfig)
$config.AllowOAuthOverHttp = $true
$config.Update()
Run the following command again to verify that the AllowOAuthOverHttp setting is now set to True.
(Get-SPSecurityTokenServiceConfig).AllowOAuthOverHttp
That is set, Good Luck :)
Refernces:
http://technet.microsoft.com/en-us/library/jj219455.aspx
http://technet.microsoft.com/en-us/library/ff431687.aspx