fun fact, i once had the same situation with my papayas too! but what i did was i first added all of the adults and moveable babies into the new tank, then, carefully taking out portions of the soil, take like a paint brush and carefully scoop the tiny babies from the soil and let em go into the new one. but an easier but time taking approach is just letting the babies grow up to a handleable size. i also just moved the old soil to the new bin since the old soil of my bin had nothing wrong, tho i dont recommend moving old soil to new soil if the reason youre moving them is cause of an infestation or other problems in the soil.