Taking off gels is a slow process. Most gels will not break down in acetone so they have to be filed off. I use a 100-grit file to take off the bulk of the gel, then change to a 180-grit and gently file down to almost the natural nail. At this point you’ll follow the same procedures as you would for blending a tip.
Graduate your files (starting with a rougher grit, which has a lower number, then moving to a finer grit, which has a higher number) to remove product, then buff the nail gently with a block buffer, followed by a 3- way buffer. If the gel has separated from the natural nail at the free edge you can gently clip this away as you would acrylic, then proceed with the graduating grit files. Remember that even hand-filing can cause friction so file slowly and gently.