If you are wearing GELIs without a top coat, or with a regular air-dry top coat, you can either peel them off or use nail polish remover. Continue to go over your nails with nail polish remover until both the color and adhesive is removed.
If you are wearing GELIs with a gel top coat, you can peel them off. If your nails are brittle, start by soaking them in warm water 5-10 minutes. Next, grab cuticle oil. Peel off one of the corners of the GELIs, and drop cuticle oil on your nail. The cuticle oil helps dissolve the adhesive, and makes it easier to peel without damaging your nails.