@RoryAlsop - I don't know why people say tools are expensive! A good socket set is around £100 - £150 in your area and the average monthly salary of your people is around £2500. The same example applies to people who live in parts of the world (Europe and US).. Here, people earn about £80 per month and a basic socket set costs about £100!!

@IanC - How do you repair a small rust spot in rear door sill of a car?

@NarimanAsgharian same way as in most other areas on a car :-)

That same way is a little bit different for me because I don't have access to special tools for the job. I only have a sand paper, original paint of my car and other basic tools.

@ScientistSmithYT - Keep us up to date about your brake issue. How many liters of brake fluid did you use for a complete change (draining, bleeding and refilling).

@NarimanAsgharian If you don't have a welding machine, you'll probably only be able to do small rust fixes, and not exactly the "proper way" (you'll be replacing metal with polymeric material). Still better than let it spread untreated though, there's a nice video from Chris Fix with a how-to: youtube.com/watch?v=n4vusY2-rkQ

Applied 2 coats of primer today, there's a part on the side where you can see a visible mark, I screwed up on the bondo/sanding on that area. But I'll leave it be and repaint it when I feel like it haha

Tomorrow I'll apply a final coat and then just wait until the paint arrives, maybe move to the rust on the other side