If I understand this correctly you need two links instead of one for the router connections.
If so, you simplest solution is to create an AE interface.
Add AE to the configuration
Move the ip address on the current link to the ae.0 interface
move the current physical link to be a member of teh ae.0 interface
add your new second physical link to the ae.0 interface
Now you have two physical links that behave as a single one. And you can add more physical links as needed in the future.
http://www.juniper.net/documentation/en_US/junos/topics/task/configuration/link-aggregation-cli.html