If you are a partner as your username suggests (@ Dimension Data), please refer to the partner Security Community for lab licensing process.
This document:
https://communities.cisco.com/docs/DOC-55301 (partner access required)
...describes the procedure in great detail.
The upgrade process is pretty straightforward. Simply read and carefully the release notes. The 6.1 release notes outline the path to upgrade here:
http://www.cisco.com/c/en/us/td/docs/security/firepower/610/relnotes/Firepower_System_Release_Notes_Version_610.html#40265