Not extruding and filament guiding tube stuck for drive gear cleaning

I am new to 3d pringing trying to clean the drive gear for an underlying problem of filament not being extruded for my xyzprinting da vinci jr.

After reading the user guide and trying reasonable first measures, I contacted tech support and was directed to try cleaning the drive gear as shown in the drive gear cleaning video (sorry I am not allowed to post links until I have ten posts, but the first link from googling da vinci jr help tutorial takes you to the "Drive Gear Cleaning" video at the bottom of the page).

Around 31 seconds into the video, and again at 41 seconds, the video shows filament guiding tube removal, which looks trivially easy and takes only a fraction of a second for removal at each end.

I've spent a good 20 or 30 minutes trying to do this, twisting, pushing, and pulling both the black plastic rings and the filament guiding tubes every which way, even pulling with all my strength.  I even carefully tried to protect the guiding tube with a cloth and use pliers to pull it out, possibly damaging the tube slightly in the process.  It's like the guide tube is welded into the feeding holes.  I called tech support a second time, and the rep suggested twisting the ring and the tube, which didn't help, and then proceeding to get into the housing as I will need to do anyway for better access.  That's when I realized I had the same problem at the extruder end, which I could grip unencumbered without removing the printer housing.  Based on the last call, I'm not sure where we could go from here if I tried calling again, and tech support won't be opened again until Monday anyway.

Is it more likely that I am mechanically inept, or that this is a printer issue, maybe related to my problem?  In either case, how can I get past this?

I don't know if this is useful, or possibly related to the above, but before calling tech support one of the things I tried was cleaning the nozzle with the "clean nozzle" function.  After nearly an hour with the extruder temperature reading 189 deg C and the display panel reading "Please Wait", the only way I was able to get out of that state was to turn off the power at the switch.  Perhaps there is more than one issue in play?