This is a common problem that a lot of people may have. When you get your glasses in the store, you should ask the staff to set well for you at that time. This kind of problem seems to be quite easy to handle, but it really need professional officers to do it. If you do by yourself, it may well be arduous but fruitless, even that it is likely to ruin the glasses. So I suggest you to bring them to the store and ask the staff to help you adjust them. Generally speaking, it will be free.
it is easy. You need use a blowdryer to warm up the edges of your acetate frame. You shall make sure to move the blowdryer to encourage even heating. And then support the glasses close to the hinge, and lay them on the temple. Then, gently put the front frames away from you ( push the frames towards the temple.) Then, your glasses frames will look smaller than it were before.
Get a blow dryer to warm the acetate frameso that the frame can become soft enough. Make sure move the blow dryer around to avoid heating one spot too much, otherwise the acetate frame will be lelt and burned. Then place the frame on an even table with on temple close to the hinge face down. Finally, place pressure gently on the temple to make it inward untill it can fit you properly.