At this moment this looks like this i want to put the new tube but cant unscrew the two piece compression fitting
... the fitting can take a allen key internally! So you stick the allen key into the fitting with the tube and turn it to the opposite direction that you turn the ripped part of the fitting you can grab with your fingers.
I think i figured this out this fitting does not come apart i have to apply the tube with force on top of the fitting no? rotary fitting turns and turns so i dont see another way and there is no screw marks visible check the photo