It is at the side of the car battery. You will need to remove the battery to access it.

 

Is it this as in picture?

 

Yes that is the wiper motor. Looks very rusty all around there!

 

Last but not the least, how do I disconnect the motor from the pointed side?

 

On the other side of the motor there is a pair of cover plates held on with 6 small screws. Remove the screws and take off the plate. Then you can unhook the end of the control cable from the wiper motor gear wheel.
Here is a page from the parts book showing the motor, which might help to make it clearer:

 

why not substitute the motor from the other XJ if the wipers are working in the other car?

Removing the wiper motor:

remove the half-moon bracket around the motor case two 7/16 bolts

pull the motor out from the cavity and VERY CAREFULLY pull the wiring plug from the motor.

To release the cable:
remove the 4 hex screws from the motor cover, they are 1/4" inch screws. Keep the motor facing up in your hands

loosen the thumb ferrule nut from the motor. you might need pliers,

pull the cable off from the pivoting Cam.

 

The motor has been removed, tested and works on ground but doesn't work when connected on the car.
below a testing video link for further assistance

 

looks like it runs so it could be the wiring connector at the motor or the switch itself.

 

The issue is the wiring connector to the motor