Asuming your driving line through the corner is correct.

Change only one setting at a time in small increments

From more to less influence

• Increase front splitter angle
• Decrease rear wing angle
• Increase front ride height
• Decrease rear ride height
• Increase front spring stiffness
• Increase front anti-rollbar stiffness
• Decrease front negative camber
• Increase rear negative camber
• Decrease rear spring stiffness
• Decrease rear anti-rollbar stiffness
• Decrease front tire toe-out
• Increase rear tire toe-in

When the car is transitioning into accelerating in the middle of the corner and the car wants to oversteer it generally means that the weight hasn't shifted to the rear enough or was too slow to transition. To help with this, we can reduce the rake, or softening the rear suspension.

Additionally in high speed corners, aero changes will also have a big affect on the balance of the car through the corner, as well as decreasing rear tire toe-in will induce a bit more stability of the rear of the car and help with turn-in.

Increasing the wing angles will impact your top speed so it is highly recommended you try to first shift the aero balance by changing the rake of the car.