Do you have to remove the inside of the stock logo (which is red) to attach this unit?

Hello, there is glue on the back of the emblem so that you could stick it directly. we provide Bluetooth control box and you will need to download an APP and open the Bluetooth to control the lights when connected with the power source.

How does it attach to grill? My 15 Sierra has the GMC letters formed into it, but has the red logo on that form

Hello, there is glue on the back of the emblem so that you could stick it directly.

Where does this ship from?

Hello, it will ship from China.

Does it fit a 2016 sierra? Or is it specifically for 2017

Hello, it fits 2011 GMC & 2017 GMC, but the dimension is 17"x3.5", you might as well measure it to check whether it fits or not.