Hi, I have a two part concrete window sill which has blown (internal metal bars have rusted). Can I remove this and replace with similar while the window is still in situ or should I take the window out first (the widow is a UPVC double glazed unit measuring 190cm wide by 150cm high). I'm willing to do most DIY jobs but I'll look an idiot if this widow drops out on the patio/my head.
Thanks, Huw.