First, you can put your glasses in water for a while. Second, put some cleaning solution into the water and try to take the logo down carefully. If the logo is just made of paper, you can just use toothpaste to rub the log gently. Avoid using something sharp such as sharp fingernail. Third, don't use strong acid or strong base because these kind of solution can react with metal and destroy your metal glasses.
There are many ways for you to move the logo without scratching the glasses frame. There is a lovely way you could use. You may use one small stick on the brand print point which will look cute and lovely. Many people adopt such way to make their eyeglasses look lovely.
Well, it seems that you really hate that kind of logo on the side of your glasses. And you do not want to scratch it off. So, what I can recommend to you is to find some thing that has the same color with your glasses frame and glue it on the logo and that the logo could be covered. That sounds great right? Otherwise you would have no options at all. Hope you find this useful.