How to change spine curves edges to circular or arc edges

I am working with a model that has a curved body or feature, that looks likes it was created with a resolve. I checked the fastener hole edge curves on both sides of this feature, which is nonplanar. One side of the hole is made up of two split arc edges. The other side of the hole is made up of two spit spline edges. The spine edges is an issue in creating a fastener in Simulate. I tied to use the Round to edit the spines but if this is the correct tool I can’t figure out how to replace the spine edge with arc edges. 

Does anyone know the approach to doing this? I only have the Creo Parametric not any advanced design add-on licenses.