>>363926650
Its hard to assign a number to it. The hardest part would be fixing all of your blendshapes that involve mouth movement
Even if you're skilled with blender its still a respectable time investment just for that reason
What are you looking to swap it for? If you're just making the teeth into pointy/shark teeth or something, you could probably just make a shapekey for that new shape itself instead of swapping out the teeth entirely.