How to remove broken compression nut from the fitting?

Hey, you can remove this by grabbing the end of the capillary with needle nose pliers and pulling it out. Sometimes some back and forth movement is necessary. You can also order the whole piece where the broken capillary is, if you think that it got damaged (likely okay): G4204-60004 | Agilent. The broken capillary is part number: 5067-4656 | Agilent

https://www.agilent.com/cs/library/usermanuals/public/G7104-G7131-1290-Flexible-Pumps-UseMa-en-SD-29000017.pdf 

Thank you for your answer. I just want to note that in the question I mistakenly wrote pressure sensor, instead of outlet filter after pressure sensor.

I'm not sure if pulling it with pliers will work since the part of the nut is also stuck inside, not just the ferrule.

We found on the internet that a tool for extracting broken nuts exists, but our service technician said that the filter head will probably be damaged, so we will be ordering a new one. We hoped that there is some easy way to extract the broken nut to avoid buying a whole filter.