Can I connect a remote control relay to a arduino uno board by disabling the remote control in the relay?
I don't like to work with mains, so I use those outlets and connect a 433MHz transmitter to the arduino to activate the outlets.

You'd have to check the frequency of the unit, and see if anyone have decoded the transmitted data package.

If that doesn't float you're boat, you could open up the unit, and remove/desolder the relay. Add a transistor, and flyback diode and you're done. Just be careful with mains power.