Yes & No.
Yes you can swap out the HD with a new drive. But you will loose the spanning of the data between the SSD & HD (Fusion Drive). So you will first need to backup all of your stuff, then you'll need to break the fusion drive back to two discreet devices. After that you should be able to swap out the HD.
Now you do have a different issue unlike the older systems (pre '12). Apple altered the HD cable and uses a built in thermal sensor in the HD. So you will need to get a drive that is compatible. This is were you can't use a 3TB drive presently. I don't know of a 3TB that would work for you.