Some time ago I made rough cuts on the windscreen and just remove the molding shape. Now I'm getting back to it and further cutting back on the front side.

The best way to attack this is by cutting back from the front center and evaluating how far more you need to go.
The way I evaluated that is by looking at the transition from the windscreen to the canopy frame. You can stop cutting back once the transiition is smooth and without a bump down.
The way I cut with the cutting disc is by making first a light pass that sets the path, then move some gentle moves back and forth going 3/4 through.
Finally I make one final pass from the edge all the way through in one pass.

As you can see, I also made some drawing on the front top skin where I think the windscreen will end up. (conservatively, because it ended up way closer towards the rollbar brace)

Another marking made, another cut, more sanding the edges and try again.

It's a try and error process that requires a lot of patience, unless you want to take the risk cutting back too far and ending up reordering your canopy and doing the whole job again.
I'm doing small sessions to stay concentrated and try not to rush this.