how to migrate confluence space from version 6.15 to version 7.1.1

[Byun hyung goo]

We managed 2 Confluence Server 

#1 Confluence server version 6.15.4 using mysql database

#2 Confluence server version 6.0.5 using mysql database 

we are planning #2 Confluence server upgrade to version 7.1.1 and database change 

Oracle  2CR1

After upgrading server 2
I want to know if it is possible to transfer a specific space of server 1 to server 2
( all contents and attach files of specific space )

And I want to know how.

Thanks 

Byun.