Aside from wanting to look good, which is an honorable goal, there are numerous health effects to exercising. If you want to lose weight long time, first you need to feel good in numerous ways. Physical exercise is a clear path to raising serotonin levels, experiencing at least some endorphin highs throughout the week, and also sleeping better which in its turn has clear health benefits. Therefore: regular physical exercise is as close we can get to hacking the way we feel about ourselves.
Of course, one challenge is to find some way to enjoy exercising. Not everyone enjoys sports and not everyone likes the sensation of pushing their limits by lifting weights. Regular long walks or bicycle riding is likely the easiest way to start building this habit. People who dislike being alone might be able to silence their brain with an audiobook or podcast. Parents might find this gives them some much needed alone time.
When feeling better about yourself, estimate how many calories you burn every 24 hours. Make sure to only eat slightly less than that every day. While working on losing weight, try to keep a deficit of up to 500 kcal per 24 hour period. It is possible to lose 1kg per week.
While it uses imperial units, this site is good for estimating how long it would take to reach a goal weight.
Also cut most sodas, most of the carbohydrate bulk (a large serving of pasta for example; turn that into a small serving and feast on the proteins), and stay off the habit of consuming sweet food. Don't try to cheat by eating lots of fruits (sugar and carbs) or trying to eat large servings of "healthy" carbs, like oatmeal. Those things can wait until the goal weight is reached.
One actual hack to eating better that might work for some people who don't experience problems living with low blood sugar for extended periods, is to practice intermittent fasting by consuming nothing for 16 hours per day. This doesn't change the body significantly, but concentrates food intake to periods when the brain is usually alert enough to make calculated decisions. Eat only between 11:00 (lunch) and 19:00 (dinner) with snacks in between that. Make sure to reach the calory goal for the day no matter if you're busy or not, or you will have a bad time.
So to formalize the path:
Exercise -> Better overall health -> Easier to eat well -> Weight loss
Just do it ™
Finally, building habits is the key to keep losing weight and to staying fit. If you drop the ball or start awarding yourself treats like overeating or skipping exercise, the habits will not settle and weight gain will return. Again, there are no hacks for this. It's necessary to keep pushing yourself until you don't really need to anymore, and by then you won't think about it much.