First of all you have do your zoning configuration and manually register your ESX Servers HBAs at the CX. After that you have to create a storage group where you put all your ESX Servers and LUNs in it.
Then you can do a rescan in VI Client -> Configuration -> Storage Adapter - please do it twice. Then when you select one of your HBAs you should see your LUNs. After that go into storage configuration an add a new Disk and format it with VMFS. That's all.
Tell me what you did already.
P.S. Sorry for my bad english
Actually there is now an ESX-aware version of the Linux Navisphere agent and rather than register the ESX by hand from the GUI, you can let the host self-register by specifying system@<SP's IP address> for each storage processor on each EMC system you wish to connect with. This is a lot easier