Hello I will help you with your question,
Its pretty straightforward, you have to remove one bracket to gain access to the starter and the work is done under the car so raise and support the car safely
Let me know if you have further questions
The undercar shield if it is still attached (they tend to get lost over the years) and the intake maniford support bracket are the only things other than the starter connections and bolts that you should have to remove.
Yes it does come out from underneath, you will have to do some juggling once you get it unbolted but it does come out
If you don't feel that you can accomplish the replacement of the starter with the instruction and diagrams from the service manual you may want to bring the job to a shop with trained and equipped professionals and have them perform the replacement for you.
Perhaps you do not have the 2.5L engine?
I suspect that you were looking at a shop manual that gives the limited instructions you gave me and you assumed that it should be done from underneath the car, which would normally be the case. However, that is not the case on this particular car. The starter cannot be reached let alone be removed from under the car, and it is necessary to remove some other parts to get to it from the top, primarily the oil filter.
If you still you were right, you might want to take a look at a '97 TL 2.5 to verify it for yourself or talk to someone who has done one, which is what I did.
Thought you might like to know so that the next time you give some expert advise on this you can provide the correct information rather than telling the person they're either not qualified to do the work or don't know what kind of car they have.