After performing an FPC0 reboot for cr2-codfw as part of T134932, cr2-codfw warned about an outdated firmware on FPC 0 (2.18 instead of 2.19). I confirmed with show system firmware that this was the case for cr1-codfw.

2016-0531-0560 was opened with Juniper for the firmware upgrade, as the jfirmware package can only be provided by JTAC and the KB with the upgrade process isn't available on the web. The process was roughly this:

<drain FPC 0: VRRP set to 50, deactive OSPF/OSPF3 interface, set et-0/* disable>
request system software add http://.../jfirmware-NNN.tgz
show system firmware # confirm the old version
request system firmware upgrade fpc slot 0
show system firmware # wait until every PIC is upgraded
request chassis fpc slot 0 restart
show chassis fpc # wait until it gets back to Present -> Online
show system firmware # confirm firmware was upgraded
<undrain FPC 0: delete et-0/* disable; activate OSPF/OSPF3 interface, remove VRRP>

(note that some of the above commands are hidden)

I performed the above for both cr2-codfw and cr1-codfw in sequence.