How to change head texture using nbt tags

So I'm creating a gui with a bag of redstone in it and this redstone bag is a head and I got the texture value (eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvODYzMjgxMzg4YzUzYjJmMDZhYTEyMThkOWZiZDMzMjI3OTdmNzhhYTVlODkzYjJjNWYxODEzMjFhZmU4NTQyNiJ9fX0=) but I don't know what to do know

https://imgur.com/a/qlgVg5N