If you have AC you have no options. The heatercore will not come out the front.
On the AC setup the heater core cover is held by 4 screws. There's one for each side of the cover. The top one is easiest to get out if the speaker is removed. The other three you can easily get from under the dash. ((You can get the top one w/o removing the speaker if you are Very flexible.))
There's a small trick to getting most of the air out.
1. make sure the radiator is full.
2. put the hoses on the heatercore but only clamp the bottom one.
3. take off the cap in the engine bay and fill the thing to the top.
4. carefully work the top hose off the heater core to bleed the air off. Don't pull it all the way off.
5. top off the engine and close the cap.