Removing the plug is a chore.
I put one in my old 300D, and used a 36" breaker bar. I almost gave up, but it finally began to turn.
If your car has a lot of mileage, the plug may need some heavy torque to get it out.

I do agree, a block heater is a nice thing to have. I personally do not use mine unless the temps go below zero F. I have always been able to start mine by simply glowing an extra time or two, and then starting her right up.

Good luck with your installation