2011 VW Passat CC temperature issue

My Passat since I’ve owned it over the last year never seems to get to operating temperature. Even on a long drive it might get there on and off a few times but only when it’s driven hard. Under normal driving conditions it gets maybe a notch off on the dash, but it will dip and rise quite frequently. I suppose the first thing to check would be the thermostat. Has anyone any experience changing a thermostat on a Passat CC? I’m told it’s a quick fix, that anyone could do but I can’t seem to find a decent YouTube video on how to do it.

I’ve had the car for over two years and the only issues it has is this temperature issue which also happens to the oil temperature. It just doesn’t seem to get up to temperature.

I wasn’t planning on looking too much into it as I didn’t have plans to keep the car long term. But I’ve fallen for her and with the mileage she’s soaking up I’d rather keep it and take the loss on the fact when I do have to sell it its gonna be with nada.

Any help would be much appreciated!