Geoc3d

Hi there I am using Cura 2.3.1 on a Mac (OSX El Capitan 10.11.6) + Robo R1 Plus and printing PLA Issue : While printing a large object the extruder stopped delivering PLA half way (jam nozzle), the printing was looking perfect ... but now the extruder is in the air ... I am not an expert but I understand that one way to try to recover the work done and restart the print is to access the G code, someone can advice if that can be done with the Cura 2.3.1 and if that is the case how to do it please? Thanks OG