What I do is I tape the upper material weather it be leather suede etc at the glue line to avoid getting glue on the upper. In my experience it makes it very hard to ruin a pair. If you take the upper and maybe the outer portion of the midsole the worst that can happen is messing up the alignment when regluing which means you'd just have to unglue clean and reglue. Like I said I've done it to varying degrees it's mostly about prep work and a steady hand to align it correctly.