iPhone 6 - Printing iMessage Conversations

Hello,

I am interested in printing a conversation in iMessage that was started in October 14, 2014. It is currently on my iPhone 6.

I understand how to print an iMessage conversation via a MacBook Pro, but do not know how to do so from a phone.

If I log into iMessage on my MacBook Pro, how can I retrieve the history of the conversation that is stored on my iPhone. (I'm pretty sure my iMessage might be backed up by iCloud!)

Please let me know as soon as possible.

Thanks,

mladha