Maintenance of the frets
Normally spoken frets do not need maintenance. Although it can happen that the position of one fret is higher than the other frets.
In this case the fret must be adjusted. To do this you must remove the strings and cover the fingerboard with tape for protection.
Now you can lower the fret with a small file or a carborundum stone. You must file in the same direction as the neck with a constant pressure. After this action the fret will be flat and must be rounded. This can be done with a small file or a special curved 'fret-file' which can be obtained in a special store.
Finally you have to smoothen the fret with a dot of fine steel wool.
Lose frets can result in clanging and rattling of the strings. They have to be replaced, this is not an easy job but with a little handiness it could be done by yourself.
In cross-section the fret is T-shaped, the stem of the T-shape has little saw-teeth which anchor in the groove of the fingerboard. The empty space between the fret and the wood must be filled with filler or glue.
To remove the fret you have to heat the filler or glue with steam or a soldering-bolt.
Than it's possible to remove the fret with tweezers or a knife. This must be done very carefully.
The most important is not to damage the surrounding wood.
After roughening the stem of the T you can replace the fret. Cover the stem of the fret with white glue before you put the fret in place. If the fret doesn't anchor you will have to buy a new one.