I didn’t bother to write a real How To, as it’s insanely simple.

Here’s how it looks when you take the bottom cover off:

Take the screws out and pull down on it to unplug it.

Swap the cage over to the new HDD by removing the 4 phillips screws on the sides.

Drop it in, slide it upwards to seat it on the connector, bolt it back down and put the cover back on.

Now you have a lot more space.