Cut Curves surrounded by Floorboards? I have not long decided to progress the carpet contained by the...

I have not long decided to progress the carpet contained by the hallway to laminate flooring. The first step of the stairs are curved and I am wondering how I can cut a surefire curve on the floorboard.

Please help.
Regards,
Answers:    using a jigsaw for most of it, if you inevitability to cut a lot rotten.. then router..it's for edging (making it smoother)
Use a curved jig to guide the saw or router.