You would have to remove the gate plate from the shifter and delete the material at the end of it so you could manually shift it into first if you planning on using the stock console shifter, otherwise, as said earlier, it's a snap of a swap.
If a column shifter, I don't think any modification will be needed.
You'll have to get a cable bracket from GM dealer to mount the kickdown cable, it attaches to the next to last two driver side intake manifold bolts. Cost would probably be approx $5.
Welcome to the club, we hope you enjoy your stay.....