Shifter Replacement
Replacing a broken or damaged shifter isn't that hard. It's re-routing the cable and adjusting the derailleur that stops most home mechanics from tackling this job at home. Fortunately, we give you information about both of these secondary tasks: see our section on cable replacement and tuning the front and rear derailleurs.
Use a butter knife to raise up the inside edge of the grip. Pour some water down into the grip.
Begin rotating the grip until it breaks free and slides off.
Loosen the bolt until the shifter slides around on the handlebar. You don't need to remove the bolt.
Either before or after you take the shifter off of the handlebar, you can take the cable out of the shifting mechanism. How you do this depends on the type of shifter.
Now slide the shifter off of the handlebar. There should be enough cable to reach if you rotate your handlebar in the direction that loosens the cable.Unscrew the cap, and you'll see a disc that rotates to pull on the cable.
Shove back on the cable so the barrel comes out of the shifter mechanism. Grab the barrel and pull the cable through.
(In most cases, removing the bolts on the gear indicator gauge won't expose the cable housing. But if you can't see any other way to disassemble the shifting unit, try it.)
Grab the barrel and pull the cable out of the shifter.
Using a pair of needle-nose pliers, gently squeeze the cable cap on the sides opposite the crimp-marks. When the cable cap "rounds up" and rotates on the cable, slide it off.
Now pull the cable out through the shifting mechanism.
Slide the shifter onto the handlebar and rotate it to the same position it had previously. Tighten it down with the hex bolt.
Now you'll need to adjust the cable tightness on the derailleur. See our section on tuning front and rear derailleurs.