but i don't want to make everything from scratch like him, I want to use a remote pressure switch from a flashlight and connect it to the push button on the laser range-finder, they are laser range-finder that have a remote pressure switch already but I don't want to buy those
So what exactly is your question? Momentary tactile switches are all around us. You can buy one for about five cents US. An OCR Tactile Push Button Switch Micro Momentary is what you want. You can also hack one from any of several sources. So what exactly are you asking or need help with?
Also the ratings(voltage current) for the switch need to be accurate. If you solder them in parallel you can use both switches. If you have more than 2 contacts, please post a picture and part number of the pressure pad switch.