Removing the E-Z Track metal rail joiner and replacing with insulated (plastic) rail joiner can be done but is most challenging. Cutting an isolating gap in rails is easier for most people. Gap does not need to be as wide as Flare wrote he uses.
Never cut gap in rail without wearing proper eye protection.
Cut gap in rail and fill the gap with small piece of styrene coated with CA to hold it place. After CA has cured, trim the styrene to match the rail profile. Be sure to remove CA residue from the inside and top of the railhead.
The gap can be made with Dremel cut-off wheel , track razor saw, or using whatever tool you are comfortable using. The Dremel fiberglass reinforced cut-off wheel is more durable but make a thicker cut than some of the other Dremel wheel type cutters. All the mentioned tools make a gap much wider than necessary for electrical isolation. A 1-1/4” Fiberglass Reinforced Cut-Off Wheel cuts a gap about 0.045 inch wide.
Click Here to view a segment from a Bachmann video. It includes the Bachmann Power Terminal with Insulated Gap track you can buy if you do not want to make what is required to use a Reverse Loop.