Cable internet and Cisco 1800 router

I have a Cisco 1800 Series Router with a internet T1 currently.  We are going to be dumping the T1 for Comcast Business internet line with 5 static IP's.

How do I configure the router to use the Comcast line as the internet connection and not the T1?  I didn't set this up originally and now it's thrown at me and I have no clue.  I'm assuming it's simple.  We also use a Pix 515 for VPN connections, but first step is getting the router to use the comcast line.
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savoneConnect With a Mentor Commented:
You will have to configure the WAN interface to use one of the comcast IP addresses.  Their commercial group is pretty good and will be able to give you the IP, Subnet and gateway you will need.

If you are using NAT to give internet access to your clients then its no big issue. Just goto the interface which had T1 earlier. There change the IP address and you are good to go. As far as the PIX is concerned. I hope that its located behind the router and will function as it is.
And further the thing like ip route Gateway of T1 will be changed to

ip route DefaulteGateway_Of_Comsats_Line.

Any other command having the T1 IP will be replaced by the comsats IP.
Simply place no before the command and then re enter it by ommiting the "no" and placing the NEW IP in the command.
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