It is on by default.
Egress scheduling is basicaly priority scheduling and is on by default. Q1 entertains packets with C
OS 0-3 and Queue 2 takes care of 4-7. So if you have a packet in Q2 it is scheduled prior to packets in Q1.
Ingress classification is based on incoming dot1q/dot1p or ISL tag or default port-based tag. it is also possible to overide the incoming tag or to rewrite to specific value. Refer to the configuration guide and command reference for more information.