Not so often needed to use by hand, configuration scripts will use such on shutdown.
Usage:
# /sbin/ip -6 route del <ipv6network>/<prefixlength> dev <device>
Example:
# /sbin/ip -6 route del 2000::/3 dev eth0
# /sbin/route -A inet6 del <network>/<prefixlength> dev <device>
# /sbin/route -A inet6 del 2000::/3 dev eth0
