Look at where the knob fits onto the shaft. Somewhere there will be a lttle tiny notch. Take a very small screwdriver, slide the tip into the notch, and pull it toward you along with the knob. Doing this releases a little clip that holds the knob to the shaft.
Yes
I was looking at the 2001 Mercury Sable Owner Guide and it mentions a TRACTION CONTROL on / off switch located to the right of the instrument cluster
You need to remove the instrument cluster or control panels you want to work on to get access to the bulb holders.
Replace the instrument cluster.
The instrument cluster needs to be removed to get at the bulbs.
It is not repairable, you should replace the instrument cluster.
Traction control
remove dash replace bulb(instrument cluster)
The speedometer is part of the instrument cluster, and is fused with the other instruments.
You have to remove the instrument cluster to get access to the bulbs.
The instrument cluster is also the body computer.
1997 Mercury Tracer Instrument Cluster Gauge Amplifier