So there are two really easy ways to resize a ring if it is too large for you, one using tape and the other glue. It goes without saying that you shouldn't use these methods for nice jewellery, just pay a bit more and get them refitted.
So this is almost too easy to make into a tutorial but when I googled it there weren't many good answers besides going to a jeweller and getting it fixed.
METHOD 1 - STICKY TAPE/ BAND AID
So in the first version all you need is sticky tape or a band-aid at your disposal. You can literally do this with your eyes closed! Just wrap the tape/ band-aid around the ring continuously until its the right size
- told you it was wayyyyy to easy! Basically perfect for last minute emergencies. But given that I have a tendency to fiddle with the tape and it gets irritating and peels its not a very permanent solution. Hence, method 2.
So your ring should now look like the picture.
Over time the glue will get cloudy but not outright dirty - so if you feel the need to touch it up, peel off the glue and reapply as needed.
Hope it helps, though I think I could've just said use a glue gun to resize your ring and all you lovelies would've caught on! =D