The Same way We make it now just with there technology
temples, statues, coffins, jewlary
iron was found by Egyptians and they used it a lot.
Ancient Egyptians did not make iron tools for the first time; they primarily used copper and bronze tools during the early periods of their civilization. Ironworking became more common in Egypt during the Iron Age, around the 1st millennium BCE, but the knowledge of iron metallurgy was likely introduced from other regions, such as the Near East. While they did eventually produce iron tools, they were not the pioneers of iron production.
iron weapons and tools
They produce large amount of iron
The Egyptians used a black stone similar to iron ore to make black eye makeup. This stone contained a great amount of lead. The stone was crushed and mixed with water.
iron use has been dated from before christ. the Sumerians and Egyptians used Iron for small objects like spear point and jewelery.
bronze and iron weapons
They traded goods, slaves, and iron products for leopard skins and valuable wood.
Egyptians used papyrus stems to make paper
I am not 100% sure if this is the correct answer since you used the word extensive... but the first people to use iron would be the Hittites.. While they created iron they could not create enough to be effective in the use of battle with the Egyptians... who used copper weapons.
Ancient Egyptians extracted iron ore from rocks using a combination of heating the rocks in fires to break them down, and then using various tools to extract the iron. This process involved a series of steps including crushing the rocks, smelting the ore to separate the iron from the rock, and then shaping the iron into tools and weapons.