Can't Undock

[Slaghead]

Ok, so I have a humble little space station that I made now that I have gotten a bit better at rendezvousing after rescuing Kerbals.  I have lost some fuel tanks and I have wasted a ton of mono propellant because I can't keep the RCS directions straight.  My makeshift node thingy is on crooked.  And I have had to dock the space station to the arriving ships instead of the other way around (this is mostly because I am bringing up way too much ship for the task).  But I have a real problem outside of this thing being a wreck.  One of my clamp-o-trons (circled) doesn't have an undock option for some reason.  I have three mini tugs attached to my station because, well, they were also how I got the original cargo up except for the actual research lab.  The connection node is the second one I sent up because I lost the first one chasing after a fuel tank that still had a lot of fuel in it.  Anyway, my problem...  I can't get this tug off because there is no release option.  I want to send up a supply ship but it's taking up the last node unless I jettison the full fuel tank on top or collect the plant test on the other side.

 

 

[bewing]

Try using this tool:

 

[Slaghead]

Indeed, this tool fixed it.  I haven't had this happen before but this is really the first time that I've tried using docking ports.  Thanks for the quick reply!  I really appreciate it.