The following documents discuss and describe the steps involved in enabling IPv6 on Juniper security products and firewalls running Junos OS.
A general guide to Juniper firewall configurations is given by this Firewalls Policy Overview and a more detailed guide is available in this CLI User Guide for Junos OS.
For more comprehensive documentation on the various versions of Junos OS and specific security products, go to the Junos OS Tech Library web page. That page has a section listing the different SRX Series security products. Juniper also maintains an in-depth Knowledge Base specific to configuration and deployment of its equipment, although it is not specific to IPv6.