I hope I can explain this correctly. The problem is not really the transfer roll. Look up how to remove the transfer roll:
Page 8 of the instructions shows you how to remove the transfer kit. If you look at picture #2, you will be looking at the paper feeding mechanism.
I removed the entire paper feed mechanism off the tracks by removing the two screws that go into the track. You don't have to do this but it made it a little simplier. Remember where the screws go back in because there is not a "hole" that the screws fit into.
Carefully remove the plastic cover over the circuit board, 2 screws I think.
If you look from the end of the paper feeder on the side where you see all the gears, you will find the plastic clutch that everyone refers to about 6 cm away from the transfer kit. It is cylindrical and has a small piece protruding from it on one end and on the other end is a gear. It is black and made of plastic . It is attached to the end of a shaft.
I think you have to loosen the circuit board by removing 1 screw. Don't pull it off, but you do have to loosen it to get the clutch off.
To remove the clutch, there is a small metal piece that fits onto the end of the shaft onto which the clutch fits. Use a small screwdriver to carefully pry that piece off. It looks like a C when you remove it. This is a tough piece to get back on but its doable.
Take the clutch off. It comes apart into 3 pieces although mine was so gunked up that it took quite a bit of cleaning to get it apart. Use a degreaser to clean it. I used a small bit of white lithium grease on the inside after I cleaned it up and reassembled it. Put it all the pieces back together and voila it should work. It jammed one more time after I fixed it, but its been running fine for the last week.
Good luck.