Check out the question below regarding headlights - it contains detailed instructions on removing the headlight assembly - which happens to be the best/easiest way to change the bulb.
And the Owners Manual also has illustrated instructions also.
See "Related Questions" below for more
No they do not
Lift hood and you will see 3 vertical screws holding headlight assy. in place.
Ask at an auto parts store.
See "Related Questions" below for the 3 primary sets of instructions by model year groupings.
Changing the assembly is pretty much the same as the procedure for replacing the bulb. Luckily Ford provides detailed and illustrated instructions on doing this in the Owners Manual. If yours isn't handy, or you like an electronic version for the computer, checkout the Related Question below for where to find one for free download. Also see "Related Questions" below for helpful user-provided information on removing/installing the headlight assembly.
Very easy. 2002 Ford Taurus. Take a look at the entire headlight assembly. Look down on the assembly and toward the side closest the radiator you will see a small bolt to unscrew on each housing. Look toward the rear of the headlight and you will see two metal clips that need to come out. A medium size flathead will get them started but they should come staight up. The assembly will now pull out of the front of the vehicle. Be sure to unclip the small wiring harness. Uncrew the back of the assembly and you will see the back of the bulb. Detach wiring. Unscrew the ring holding the lamp. Remove old bulb. DO NOT touch the glass of your lamps! It will cause hot spots and the bulb will burn out. Take new bulb and notice the notches...they will orient the bulb correctly. Screw on ring. Attach wiring. Screw on the back of the assembly. Attach the wiring and install back into the front of your vehicle.
take the headlight assembly, and remove the light out of the car (if the bulb is halogen don't touch it use a glove as the oil on your hands will prematurely wear the light, take the light out of the assembly use something like a hair dryer and carefully blow the hot air into the assembly keeping the light socket hole upwards make sure you don't melt the assembly if you use a heat gun once the moisture is out replace the light and assembly
I believe the "Related Question" below specifically addresses replacing the door glass on a Taurus / Sable.
On the bottom.
there is a plastic clip that holds in the bulb on the back side of the headlight under the hood, its a circular clip that turns either way and on some vehicles you have to take the whole fixture out(like a 2000 ford taurus) then the bulb comes out of the headlight assembly and has an o-ring that seals the water out and holds the beam in
The headlight relay on a 1998 Ford Taurus SE is in the fuse box in the interior of the vehicle. It is at location #22 and is a 30 Amp fuse.
The Taurus and Sables come off the same assembly line - using many of the same parts. If the engine is the same - same year of vehicle - etc., then it is very likely the engines would be interchangeable.