If you were to take the guitar to a luthier they would glue the offending frets down. Here's what's involved:
- A coat of wax is applied to the fingerboard on either side of the fret.
- Liquid thin CA glue is applied to either side of the fret.
- The fret is pushed into place.
- Accelerator is sprayed on the fret.
- Clean up.
- Spot level, crown, and polish.
- Restring and set up.
A small precision straight edge can be employed to push the fret down and bridge the adjacent frets. If done carefully, the fret will not require spot leveling, crowning, and polishing.
This is an intermediate level repair. It requires some tools and knowledge of methods and materials. As always, if your precision tools must be held tightly as you swing them, take this to a pro. You may be surprised at how inexpensive this job is.