Probably the easiest is on E-Bay.
No
No
Be more specific.
Pull the dash trip off gently from bottom to top, (just the dash trim by the climate control) and there will be 4 screws on the climate control module. Its best to buy a used 1996-1999 Mark VIII Climate Control module, since they have "Hard Buttons" on the climate controls. Pull out the old one, and replace with the new model. Newer model climate control modules are totally compatible w/the 1993-1996 models.
Center dash above the console.
Below the climate control and back of center console.
cruise control switch
no
go to markviii.org. they have a answer for almost anything with the lincoln mark viii
Bad thermostat?
Where to find the horn relay fuse for a 93 Lincoln Mark VIII
http://www.markviii.org/LOD2/Thermostat.htm