Is there a possible way to make function to a bunch of bricks with short coding?

You are able to iterate through the descendants of a model to edit properties of the instances inside.

local model = --model directory here
for _,v in pairs(model:GetDescendants()) do
	if v:IsA("Decal") then
		v.Texture = "" --new texture here
	end
end

GetDescendants returns a table of all children inside of an instance (including children of children, and so on). You can iterate through this table, and check each instance in the table to see if it is a decal, and if it is, change its texture.