Print as two pieces, then attach with M3x30 screws padded with 3 washers. Also insert a washer between the extruder and the motor to get the positioning right.
If the screw holes are too tight, either file them out with a needle file, or print with an extrusion multiplier of 0.85 or 0.90.
One word of warning. This works with the original extruder provided with the Folgertech 2020, but if you have replaced it with some alternatives (such as http://www.thingiverse.com/thing:650957), it won't fit. Take a look at the comment thread on http://moosteria.blogspot.com/2015/08/a-new-hot-end.html for some discussion.