Avoiding seed oils is a never-ending battle in the modern world, but one well worth engaging in.
To recap the basics: seed oils promote systemic inflammation in the body. Avoid any seed/vegetable oil you come across except for these three oils: single-source olive oil (ie: 100% California), avocado oil, and coconut oil. Those are the only three you have to remember! Don't be fooled by 'non-GMO sunflower oil' and the like - they are to be avoided as well.
The easiest way to do this is 1) cook/prepare your own food, 2) do not buy packaged, pre-made, or processed foods and 3) avoid 'false friends' - foods that are packaged or marketed to look like healthy alternatives but actually are not.
Initially, this will seem like a daunting if not impossible task but I can tell you that I have been 95% seed oil free for over two years and it is actually a much simpler and often times cheaper way to feed yourself, not to mention the numerous health benefits. I have no desire to ever go back to consuming seed oils on a regular basis.
Your grocery shopping will take place almost exclusively in the meat and produce sections. Also, the stores with bins of nuts (not granolas or sugary snacks!) that you scoop out and pay for by the pound will come in handy too.
Again, this seems daunting at first and you may crave fast food fries, a bag of Doritos, or a box of Oreos at first but this craving will fade and you will develop a strong distaste for these items. They will taste 'fake' compared to your new diet and you will feel a lot better and have a better chance of avoiding chronic illness as a result. Also, depending on your lifestyle, it may require a new approach to eating and some planning ahead. Yes there will be times when you will need to dine out or have no other choice for caloric intake except for seed oil ridden food, but you want to get to a point where these are infrequent exceptions.
I strongly believe that anyone can complete this challenge regardless of life factors given the proper approach and some planning. You will not regret it.