Rental property already like that.Drill the screws and use a screw extractor.
Failing that, you will need to break the handle where screws are, basically destroying it so you can grip the screws with grippers.
Who rounded those screws like that???
Failing that, you will need to break the handle where screws are, basically destroying it so you can grip the screws with grippers.

If you can lay your hands on a left-handed drill, the torque, heat and vibration will often wind the screws out.How is the OP going to break the handle without messing up the screw threads running through the uPVC?
Your suggestion of a screw extractor might work. To be honest, I have never had any luck with them in the past.
I normally drill the heads off and then, as you said, you mole grips to remove the rest of the screw.
Those handles are brittle.How is the OP going to break the handle without messing up the screw threads running through the uPVC?
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local