As you know from previous posts, on this blog and the SharePoint Team Blog, Service Pack 1 and the June cumulative update have been released for Office 2010 and SharePoint 2010 Products.  If you are running Office Web Apps on-premise, you may be wondering which updates to install and in what order.  The following table provides a list of updates to install and the order in which to install them depending on your environment.   Pick your environment in the left column and from the corresponding right column, apply the updates in the order listed. Be aware that if you are installing the updates to a server farm, the updates must be installed on every server in the farm.  Run the SharePoint 2010 Products Configuration Wizard only after all updates are applied.

If your environment includes:

Apply these updates:

SharePoint Server 2010 + Office Web App Farm

Step 1: SharePoint Server 2010 SP1: http://support.microsoft.com/kb/2460045

Step 2: Office Web Apps SP1: http://support.microsoft.com/kb/2460073

Step 3: SharePoint Server 2010 June CU: http://support.microsoft.com/kb/2536599

Step 4: Office Web Apps June CU: http://support.microsoft.com/kb/2553919/

 (NOTE:  The Office Web Apps updates for Excel Web App are included in the SharePoint Server 2010 June Cumulative update.)

 Step 5: Once you have finished applying all the updates, run the SharePoint 2010 Products Configuration Wizard or "psconfig –cmd upgrade –inplace b2b -wait” one time on every server in the farm.

 Optional patch:

2553935  Description of the Office Web Apps hotfix package (wacproof-sv-se.msp): June 28, 2011 *NOTE: Only needed if you have Swedish language pack installed.

 

SharePoint Server 2010 + Project Server 2010 + Office Web Apps Farm

Step 1:  Project Server 2010 SP1: http://support.microsoft.com/kb/2460047

(NOTE:  This update, (2460047) Project Server 2010 SP1, includes SharePoint Server 2010 SP1 and Project 2010 SP1.)

Step 2:Office Web Apps SP1: http://support.microsoft.com/kb/2460073

Step 3: Project Server 2010 June CU: http://support.microsoft.com/kb/2536600  

Step 4: Office Web Apps June CU: http://support.microsoft.com/kb/2553919/

Step 5: Once you have finished applying all the updates, run the SharePoint 2010 Products Configuration Wizard or "psconfig –cmd upgrade –inplace b2b -wait” one time on every server in the farm.

Optional patch:

2553935  Description of the Office Web Apps hotfix package (wacproof-sv-se.msp): June 28, 2011 *NOTE: Only needed if you have Swedish language pack installed.

 

SharePoint Foundation 2010 + Office Web Apps

Step 1:  SharePoint Foundation 2010 SP1:  http://support.microsoft.com/kb/2460058

Step 2:   Office Web Apps SP1: http://support.microsoft.com/kb/2460073

Step 3:   SharePoint Foundation 2010 cumulative update  http://support.microsoft.com/kb/2536601

Step 4:   Apply the following 3 patches for Office Web Apps:

2553924  Description of the Excel Web App hotfix package (xlwacwfe-x-none.msp): June 28, 2011 - http://support.microsoft.com/kb/2553924

2544029  Description of the Excel Web App hotfix package (wacmui-xx-xx.msp, xlwacmui-xx-xx.msp): June 28, 2011 - http://support.microsoft.com/kb/2544029

2553919   Description of the Office Web Apps hotfix package (wacwfe-x-none.msp): June 28, 2011 - http://support.microsoft.com/kb/2553919

Step 5: Run the SharePoint 2010 Products configuration wizard.

Optional patch:

2553935  Description of the Office Web Apps hotfix package (wacproof-sv-se.msp): June 28, 2011 *NOTE: Only needed if you have Swedish language pack installed

 Hope this helps!! You can also find this information on TechNet.