You need to remove the hub assembly and replace it. It consists of bearing, studs and speed sensor. The wires are attached to a connector which is clipped to sensor shield. You cannot remove sensor on Montana without removing the hub. The sensor is a part of assembly.
The fuel level sensor is located in the fuel tank and is mounted on the fuel "sender" assembly. This is the assembly that contains the fuel pump. The sensor comes as a unit with the attached float. The sensor can be changed, separate from the fuel pump, but it may be a good idea to change the whole assembly while you are there IF you have had any problems with it. But you can save a little money by just changing the sensor. You will have to drain and remove the fuel tank to get to the assembly.
The sensor is located in the sensor assembly. It is inside of the transmission, the pan will have to be dropped to gain access.
its part of the mass airflow sensor screwed into the airbox assembly.
If it is 4x4 remove axle from wheel bearing assembly and then remove the wheel bearing assembly. Make sure the tone ring (looks like a ring with teeth) is still attached to the spped sensor side of the bearing, if not, replace wheel bearing assembly with an assembly that comes with the speed sensor. Replacing a speed sensor without a tone ring is pointless because it won't work.
Nothing. The knock sensor is a passive part that will not affect how the engine runs.
First try to locate the air cleaner assembly. Once this is found, locate the air hose that leads to the carburetor from the air cleaner assembly. Disconnect this hose from the air cleaner assembly and the mass airflow sensor will be visible right at the outflow mouth of the air cleaner assembly. The intake air temperature sensor is located as a component part of that mass air flow sensor.
The encoder motor sensor is found inside the front of the transfer case. The sensor motor assembly is removed with 3 - 15mm bolts after the front driveshaft and electrical connector are disconnected. The encoder motor sensor is under the big gear on the back of that assembly plate.
You can not replace just the tire pressure sensor on a Boxster. You will need to replace the whole sensor. The sensor is located inside the tire assembly.
the speedo sensor is on the top of the gear box, its held on with 2 bolts and points into the flywheel/clutch assembly.
On the EGR valve assembly.
That is incorporated with the latch assembly.