Replicator 2 extruder replacement with no overheating issues

As many friends here, I was suffering overheating problems in the rep2 extruder mod downloaded from thingiverse. This heat causes a deformation in the extruder pieces and the system starts to lose strength and print worse with time.

Bored about this problem (I replinted 4 or 5 extruder mods) I decided to design an easy and cheap way to replace the extruder with same printing results as a new extruder mod but with no deformations due overheating.

I bought a plunger from farnell:
http://es