Allo mickeymbbc
That's a tricksy question, without knowing at least what country you're in, let alone what town/city
Do you have a local engineering company/firm within easy access to you? All you'd need to do is to mark-out where you want the window cutting (ideally on the inside of the panel and the more accurate you can get it, the better), it should only cos a few $$/££/groats/shekels/whatever