How do you do co-op in uncharted 2 mission?

Answer 1

unfortunately, there are no co-op possibilities for the campaign missions, and 2 players can not play together on the same console at all.

However, you can enter the multiplayermenu and choose to invite a friend or just play with random people in a private or random online co-op match.

Answer 2

You must first download it off either the Xbox Live marketplace or the PSN market. Then go into multiplayer on Red Dead Redemption and then press back on xbox select on ps3. There will be a playlist called Co-op missions or something like that :)