Don't know how nice the pond is and whether or not you may get joy from it later in life but if it is a nice feature (other than for kids), as an alternative you could make it child-friendly. I've see lot's of this type of thing done also on TV where a grid bolted is place over the pond,. The fish continue to live and breath, kids learn something about fish insects and birds and you can remove it later to restore the feature. If it's big then a secure fence will do the job.
All this assumes the feature is worth keeping as a future asset to the garden and kids when they are older. If you must rid yourself of the pond then giving the fish to a charity or selling to a deal may be an option. As for the structure itself it depends how big it is and whether it is lined and how it's fed with water (stream or filled from your source). If it's lined you will need to remove that or make large holes in it to make sure that and soil you dump in will not simply wallow in a rainwater mudbath. Other than that it's a simple enough process of brawn.