Thank you for your question. It is possible to remove the area of filler you do not like. If the removal creates asymmetry you may have to use some product to compensate.
Although it is less likely for filler to migrate up to a higher point (it is more likely for it to migrate down with gravity) it is possible. If the filler you received is indeed Juvederm you can ask your practitioner to remove the migrated or excess Juvederm with hyaluronidase. This is an enzyme that dissolves the hyaluronic acid based filler of which Juvederm is one. Be aware that there is a small risk of allergy with the enzyme so you should be with a board certified dermatologist or plastic surgeon that is aware of these risks and how to treat them if it happens. Hope this is helpful.