I try to remove rail connectors from N scale fast track, but only one will come off.
I ruined 3 tracks before I gave up. Is the a special tool or track or method I can use?
Assume what you are calling 'fast track' you have Bachmann Snap-Fit E-Z Track.
Yes, it is difficult to remove rail joiners. Easier and faster to gap and fill rails than replacing the installed rail joiners with insulated (plastic) rail joiners.
What is gap and fill rails? I'm just starting out.
Gap – made by cutting the rail
Fill – any insulating material added to keep the rails from sliding together