Adjust using warm waterUpdated a year ago

Fill a shallow bowl with warm water (<50°C / 122°F)
(If it is too hot to touch, the water is too warm!)

Submerge the frame in the water face down with the arms out of the water as shown below:

Once sufficiently heated (30-60 seconds), the frame will become flexible.

Now adjust the frame, gently bending the frame back into alignment, like below:

Voila! Your sunglasses are back to a perfect fit.

Test the sunglasses and repeat the process if they still need some work.