206 manual transmission oil change?

Friends about 2000 km ago, the transmission of my vehicle changed. I did not like the oil that was put in. They put oil from the same barrel and sent it to every vehicle going there. I want to change this oil myself. I only paid attention then the battery was removed and they put the oil from there. As far as I can see, there was a sensor in the gearbox, they took it apart and put it there. How can I do this job the easiest. There are transactions on some vehicles on the Internet related to transmission oil change. Discharge type separate oil addition plug. Is there such a stopper for adding oil in our gearbox, or should I disassemble the battery and remove that sensor and add it from there? A brother who works in Honda brought 2 liters of 75 90 oil and I want to solve this job without paying for labor. I am waiting for the help of friends who know who knows.
My car is 2006 model diesel 206 manual.

yes let's get the recommendations :)

As you mentioned, it is added under the battery. It's the simplest place if you do. In some places (including automatic gears), they press with the machine from the bottom drain.

Come on, we're going to deal with it now. Thank you again.

I have the same vehicle in me and I am thinking of changing it. I wonder the result after the application.

I have not changed yet, I am walking in the oil trunk. The process is as follows: Under the transmission, there is an oil drain bolt. The main oil to be removed remains under the battery. The process is okay when the battery is plugged in and the battery connections are gathered as before. I asked the master, I will change to 20 tly.

Let's see what our masters say: D