It honestly doesnt matter if your motor is TDC, Just make sure you put a service bolt in the exhaust camshaft before removing it. And replace the head bolts.
Once you get the head off, Just rotate the crank side to TDC.
If you have everything TDC Already though, you can mark the camshafts with a paint marker Right where TDC is when you remove them. That way you dont have to try to align those little Dots on the camshaft. The Paint marker is bright and noticeable.
Just align the paint back up when you go to re-install them and your good to go!