I am a time served painter and decorator, with more certificates than you could shake a stick at. (A lot of studying, happy F@§Xing memories). Anyway, if there is a cheap way to get piece of the wood and paint tested, try that first, there might not be any lead and like Rik said a painter should know how to handle it. But, make sure you stipulated NO DRY SANDING in or around the house.
The method I would use is, Liquid paint remover, it’s messy but you won’t get dust in the air or on your skin. I was an apprentice in the 1970’s and the British had stopped using lead paint for woodwork at least a decade before that, I suspect the french did likewise. I have worked with lead paint for many years, but always on iron. Most lead paint used on woodwork was white or light in colour, although it was probable use in a lot of colours. If you can get the doors dipped then do so, then that’s half the problem taken care of.
If you do it yourself, Take the door out back and lie them flat, then apply the paint remover, You might have to put on 3 coats and leave it for hours, you don’t have to scrap off between coats, if you see it drying out put more on the dry areas. Try and understand the instructions, as there are various types, follow the instructions until you get the hang of it. As for the frames and windows, you will need lots of thick plastic or rubber sheets and masking tape, Test the paint remover on the sheets before you begin, the sheets might melt.
It’s a hell of a job, avoid doing it yourself unless you really want to give it go. Some people like doing this sort of thing, but then they’re usually accustomed to wearing thickly padded overalls