It would be much easier to cut out an entire surround at a junk yard and cut patches as you need them.

Working the shapes that you need would require advanced metal fabrication, not body work.

The body work would come after the welding.

I would cut the roof about 6" back from the wind shield, then remove the cowl and see where you can cut the bottom.

Save any blades you break, in case you need some short blades.

The junk yard may offer cutting for a modest price, especially cutting the roof.

If the windshield is not broken in the process, it may be useful as practice.