Is dissolving another practitioner's filler difficult to do? (Photos)

I want to get some old filler (I think Juvederm) dissolved and can no longer travel to where the doctor who injected is located. If I know (approximately) where the filler is, could a different doctor determine exactly where it is, and how deep it is in order to dissolve it? Some of it appears to have migrated, so I can't say where it is for sure? Is there a palpable difference between hyaluronic acid filler and my dermis?