I actually believe that the instructions that you are given when you press "Load Cartridge" are actually for Re-Loading a cartridge... which is what we will be doing 99.9% of the time after we have our Cube up and running.
The "Load Cartridge" process seems to assume that your are CHANGING cartridges, which is the thing we will be doing after the first load. It is actually describing the "Re-Load Cartridge" process.
Obviously, describing steps that do no apply for our initial setup can be confusing. So, here is the process that is presented to you and some explanations as to whether or not it applies to the initial cartridge.
1) Cut the External Material, leaving 6" of material outside PrintJet (Ignore)
This first instruction assumes that there is already material in the Printjet. You can ignore this instruction when loading your first cartridge.2) Pull Filament (Ignore)
Again, this instruction only applies if filament is already in the PrintJet. Ignore this instruction when loading your first cartridge.3) Replace Cartridge (Install New Cartridge)
They actually mean EXCHANGE the cartridge, which gives away the fact that the first steps were for Re-Loading and not for the initial cartridge. This is actually the first step we need to care about. First time users can simply put a new cartridge in the machine at this point.4) Insert Tube into PrintJet
Steps 4 and 5 now apply to anyone needing to load material into the PrintJet. The tube guides the filament from the cartridge to the PrintJet. Without this guide, the filament may have a tendency to tangle since it has been wrapped around a spool.5) Insert Material into Tube until it stops
The filament is fed into the tube guide. Feed it until it enters the PrintJet housing. You will hear a whirring sound at this point. That is the feed mechanism picking up the filament and pulling it into the extrusion head.
You may see some plastic emerge from the tip. That would be filament used in the testing process in the factory. You probably will not see your green filament being extruded until you actually print an object.