Replacing Duster Trunk Gutters

Hello,
I would like to ask some advice from yall. I'm about to start tackling some of the body work on my 73 duster. I've never really done any projects like this so i'm not exactly sure how to go about it. The corners of my trunk gutters are rusted out. It looks like they are secured to the surrounding sheet metal with spot welds? Its a little hard to tell. I was thinking of just cutting out the rusted areas and welding in a patch. Is it best to just cut through both pieces of metal and weld in the new patch? or should I try to remove the spot welds and then get the patch section in?

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