If you are okay with cutting the spine off, you don’t need a big hydraulic cutter to do it (even though it is objectively the coolest way). Clamping a straighte

If you are okay with cutting the spine off, you don’t need a big hydraulic cutter to do it (even though it is objectively the coolest way). Clamping a straightedge to the book and running a knife along that edge will cut a handful of pages very cleanly, you just run the knife through over and over. A metal ruler and a Stanley knife will do this just fine - heavy pressure on the ruler and light passes with the Stanley knife. (This is what amateur bookbinders do to trim the edges of books they’re binding when they don’t have access to proper guillotines.)