How to change a brake light switch on a 98 mercury mystique

SOURCE: brake lights for a 1996 Mercury Mystique

The "multifunction switch" is bad. In the old days, this was called the turn signal switch. The brake light wiring for the two non functioning lights goes through this switch. Have your mechanic check the wiring into and out of this switch. It's in the steering column.
Charlie

SOURCE: How to change transmission fluid in a 98' Mercury Mystique

you have to take the transmission pan off of your transmission to corretly change the fluid and the filter you should take it to your local shop and have done the average price for this is around 125

SOURCE: 1998 Mystique brake lights don't work while the window brake light does work.

Try a continuity test, not sure where to find the electrical scheme but if you obtain it, use a tester or borrow one to test the continuity of the wires of both taillights, could be simple as a cut wire.

SOURCE: valve cover gaskets

Valve cover gaskets are a snap, even for a real dummy.  Get a set, don't fall for the "BEST IN THE MARKET".  All you need is a cheap set of something, that will seal the covers.  Get a small tube or bottle of NON-HARDENING sealer.  Clean both surfaces , put some sealer on the engine, and the valve cover, put the gasket in place and tighten it down to a few foot pounds of torque.  It doesn't need to be cranked down tight enough to hold back an elephant, just enough to squeeze the gasket.  Let it dry overnight before you start the engine.

SOURCE: replacing cam shaft sensor in 98 mercury mystique

down by the harmonic balancer or by the flywheel you will find the cranksensor one screw or two and disconect the pigtail your done