I made another layer for this. If you see jaggies, just use the eraser to remove them. Make sure that the eraser is small enough to just remove the jaggies. Erase then merge the layers.

You can use Unsharpen Mask.
USM (Filter-Sharpen-USM) Amount: 500% Radius: .2 and Threshold: 0 Repeat the USM Filter. This may produce JAGGIES. If this happens you can back up, make a layer and erase the jaggies then flatten it.