Sure.

1) Since they are impossible to naturally tell the difference between clear you cache on your Xbox 360 (sorry but you'll have to re:download all updates for games after doing so)

1.2) To clear the cache on your Xbox 360 do the following,

Visit this link from Offical Microsoft support,

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2) Now,you will have no title updates on your console what-so ever. Play Call of Duty 4 and it will ask you to update,select yes and it will download the new TU.

Now that you've got this much done,follow what it says in this link and you should be good,

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Something to note:

Once you have the TU you would need to patch the xex's for them to launch using that TU,that's a more complex process.

As far as I know CoD 4 works, But MW2? NO!