Wire snips, or end cutting pliers (which is what I use), are best, but toe nail clippers are acceptable, too. Assuming its zip ties - cheap, readily available, no special tools required, cutting the little "box" off, rather than attacking the tie itself is the correct and safe way to remove them. as @yakitori said above.
If you only have a tiny screwdriver (and four hands) you can carefully lift the little plastic tab inside the box with a tiny flat head screwdriver, allowing the band to slide free - but under no circumstances should you try it alone, or with less than perfect vision - better to head to the hardware store/farm store and get the proper tool.