Another brilliantly worded question with absolutely no information like year, make, model, engine. Sure to get equally as worthless answers .

some are easy to do while others can be a nightmare to do. it depends on the make, model, year of the vehicle.

Most heater core replacements are long, hard, and very involved to do.

It'll either suck to do or be very simple

When they leak you have to.

No thanks - Works good...