As topic, if you wan to craft, you make socket in normal roshan or unusual ro3?

is it 100% successful for adding gem to socket?

any extra material need?

100% success. u need unusual roshan.

if u wnt to use normal roshan, u need to have artificer's brand

how to get artificial band?

make one. but too much hassle

how if unusual roshan, let say i have a diretide, i wan change it to lava, just add the lava gem and color inside only, the original diretide gem will gone is it?

Yes and yes and yes. the new one will override the old one

Is that mean we are the one who create those special courier? Mind to comprehensively share how?
Sry for beginner question.

It's best you just trade/buy those unusual couriers, cause to make it unusual you need the Artificer's Brand, which can only be obtained through craft, the recipe however:
Artificer's Brand Recipe

It looks very time cosuming by getting it via Artificer's Brand.