No...It will be a little difficult but you don't need to take the solenoid off.
It is attached to the starter, which is under the car. Look for the rear of the starter sticking out on the driver's side of the car. Remove the housing cover (3 bolts), and then the 2 bolts hold in the starter to remove it and gain access to the solenoid. TD
on the starter , which is between the motor and the firewall. and under the intake man.
If you mean the starter motor/solenoid unit it's located near the bottom of the engine block between the block & the firewall. You access it from beneath the vehicle after removing all of the plastic mud guards.
Disconnect the battery negative cable.Jack up the front end.Chock the rear wheels.On the passenger side on the front of the flywheel housing is where your starter should be. It might be on the opposite side (I'm not familiar with the Grand Marquis), but it'll be connected to the flywheel.Unbolt the two or three bolts which hold the starter in place. It will pull out at this point.Rotate the starter so you can access the studs on the back of the solenoid. Unbolt the nuts off of the solenoid, and remove the wires (they're just ring terminals, so they should pull right off, although you might need a slotted screwdriver to help with this process).Installation is the opposite of removal.
open the hood, look at the battery, trace the wire from the battery leading downward to the starter and solenoid. It will be in the front section, however, on the underside, so possibly not visible right away. You may access it from underneath the car. The solenoid sits on top of the starter, you will see them, they are both cylindrical in shape, the starter being much larger than the solenoid.
Follow the Youtube instructions.
remove engine cover
In the trunk on the drivers side ( behind the trunk liner ) I assume there is an access hole )
It is inside the fuel tank, removal will require access to the top of the fuel tank.
Replace Remove starter Remove solenoid at top of starter Remove front end of starter for access Remove locking washer from starter shaft Drive should slide off shaft
On the left side of the trunk behind the trunk liner ( I assume there is an access hole )
On a 1996 Mercury Grand Marquis : The fuel pump shut off switch ( inertia switch ) is in the trunk , behind the trunk liner on the drivers side of the trunk , near the drivers side rear tail light ( there is an access hole )