How do I get on with e-filing, since the taxes have already been paid to CRA ?

Could you provide more details regarding what you are trying to accomplish? E-file is used only by professional tax files. I think you meant NETFILE.

Yes, I meant Netfile

Thank You !

Under File, you'll see the "Pay and prepare to file" screen. Select 2 "File your return". This will allow you to NETFILE.