Phase it by flow. Keep the old path open until the new one is proven.
Every trade in the room. A drawing walkthrough. Every non-obvious decision called out with its intent.
Mechanical to electrical at the panels. Electrical to controls at the Aux I/O and WMS interface. One trade owns each side.
Every vendor working from the same scope. Each RFQ checked against the released drawing.
How field changes get documented, who approves them, how they return for as-built updates.
Bring it live a zone, a lane, or a flow at a time. The old path keeps running while the new one is proven.
For every phase, know how you fall back. Keep the manual path open until the new one is accepted.
Schedule disruptive work off-shift, between waves, on a light-volume day. Never against a truck that has to load.