Encontrou um site com a resposta. Para resumir:
Create the following folder structure:
C:\Office2010\ C:\Office2010\DVD\ C:\Office2010\SP2\ C:\Office2010\SP2\extract\Extract the SP2 files (link in question) to the SP2\extract folder.
Execute
"C:\Office2010\SP2\officesuite2010sp2-kb2687455-x86-fullfile-en-us.exe" /extract:"C:\Office2010\SP2\extract"from the Administrative Command LineAccept the EULA
Insert your Office 2010, and copy the contents to the
Office2010\DVDfolderCopy all the files from the
C:\Office2010\SP2\extract\to theUpdatesfolder inC:\Office2010\DVD\
Você pode gravar o DVD ou executar o arquivo setup.exe para instalá-lo no nível do Service Pack 2