Hi,
There is not big deal with this, if you have experience configuring VoIP, that would be enough. Just make sure that when you creat your voice-peers the point to the CCM IP address (or DNS) for calls going to your IPTelephony net.
In the CCM 3.0 you should configure in the Gateway part a name for the AS5300 and the IP address of it. So in your route plan you shoul state that call tha are out of your net should go to the Gateway (AS5300).
Some times is recommended to type command such as "gateway" in you global command config and also type the same name you state in the CCM.
Here you have an interesting link that could help you. Just be carefull that this links talks about VG200, but is the same IOS for the AS5300.
http://www.cisco.com/univercd/cc/td/doc/product/voice/c_access/vg_200/sw_cnfg/voice.htm#29402
hope it helps
