Hacker help: How do I cut the bed legs?

Materials: Nyvoll bed frame

Description: Our new mattress is much taller than our old one and now my feet don’t even touch the ground when I’m sitting on the edge of our Nyvoll.

I’d like to saw 6 inches (15cm) off the legs but I’m not sure if a simple hand saw is the right tool. Will the veneer split? Will the core crumble?

The product homepage is here.

Product description
Bed frame:
Main parts/ Headboard: Particleboard, Foil
Leg/ Leg, headboard: Fiberboard, Foil, ABS plastic

Thank you in advance!

~ Scott, Vancouver, Canada

Photos: IKEA.com