Use this topic:
http://forum.mikrotik.com/t/dscp-mangle-and-queue-trees/100297/1
you can use that to get started. setup the WAN first - setting the wan interface name (i use “wan0” and “wan1”). Make sure you set the correct upload speed.
You can do the same for your LAN. Though the script will duplicate your Mangle rules, so you will have to remove the duplicate set.