Basically, you need to do two things:
change your server-side configuration to include an endpoint with the netTcpBinding (this can be in addition to the existing wsHttpBinding endpoint - no problem)
add the netTcpBinding to your client's config file as well and selecting that endpoint when you connect
You should have something like this in your server side config:
<services>
<service name="YourService">
<endpoint name="something"
address=""
binding="wsHttpBinding"
contract="IYourService" />
</service>
</services>
Just add an endpoint for the netTcpBinding:
<services>
<service name="YourService">
<endpoint name="something"
address=""
binding="wsHttpBinding"
contract="IYourService" />
<endpoint name="something"
address="net.tcp://YourServer:7171/YourService"
binding="netTcpBinding"
contract="IYourService" />
</service>
</services>
Now if you're hosting in IIS, you might run into some problems - you need to configure IIS7 (Win2008 or Win2008R2 server), and in IIS6, you won't be able to host your netTcp service in IIS6 :-(
Same thing on the client side - add a second endpoint for netTcp:
<client>
<endpoint name="something"
address="http://YourServer/SomeVirtDir/YourServiceFile.svc"
binding="wsHttpBinding"
contract="IYourService" />
<endpoint name="netTcpEndpoint"
address="net.tcp://YourServer:7171/YourService"
binding="netTcpBinding"
contract="IYourService" />
</client>
and now when you create your endpoint in code, use the named endpoint:
YourServiceClient client = new YourServiceClient("netTcpEndpoint");
That should be all, really (unless CSLA requires something extra which I wouldn't know about.... I know "plain-vanilla" WCF)