T-SQL (SS2K8) :: Updating Rows In Batches?

I have a production table with 400 million rows.

I have a staging table which has 48 million rows. This data is the same as the production data, except one column has a different value.

Create Table Production
(
Id Int Identity(1,1),
Code Varchar(20),
ReferenceSequence int
)

-- Staging Table

Create Table Staging
(
Code Varchar(20),
NewSequence int
)

I need to update the production table with the newSequence value from staging to replace the ReferenceSequence. I.e:

Update Production

Set ReferenceSequence = Staging.NewSequence
From Staging

where Production.Code = Staging.CodeHowever, updating 48 million rows at once will generate a lot of logging!

How can I do 1 million rows at a time, commit the changes then do the next million?

I've tried some of the examples on the following page [URL], but they look to just update the tables with the same values.