Nothing about it
Installing a spoof chip requires a Hardware + Logic [Logic] (2) Test.
Installing a modification always uses the Mechanic skill relevant to the vehicle (Automotive, Nautical, etc.). The installer makes a (Mechanic Skill) + Logic [Logic] (threshold, 1 hour) Extended Test, applying all appropriate modifiers from the Build/Repair Table (p. 146, SR5).
Removing a feature should probably be treated the same as installing it without the trouble looking for parts.
So just use the Gridlink and the Pilot modification as basis to create the throwback.