Please give me some inputs how to do this.
First you have to buy one of the guns.
That style gun was on Operation Wolf, Operation Thunderbolt, Terminator 2, and alot of other games like that.
You can recognize them because the gun is mounted to the control panel with a stick coming out the bottom, usually to a large rectangular base.
The optical light guns are usually tethered to the cabinet by a long cable.
Once you have the gun, you will need to interface it to the computer.
That can be done with the A-pac from Ultimarc, the AKI from DaveB, or by doing a controller hack like you would for a Star Wars Yoke.
The goal is to convert the analog data from the gun base to something usable by the computer.
The gun is literally a big analog joystick.
It has two axes, which correspond to horizontal and vertical aiming adjustment in the game.