How to Download Complete Message Class ?

Hi ,

I have a Z Message Class. How can i download it to a file, say a text file ?

If i download it from Sandbox, can i upload it to Development someway ?

I have developed some objects in Sandbox which use messages from a new Message class. I want to use the same message class in Development as well back it up as a copy.

Is there a program that can download Message class ?

Please help.