Hi there....I'm in search of wisdom.....
My dishwasher leaked and slowly destroyed my engineered hdwd floor.
I plan to replace it with Brazillian Cherry 3/4 in. but my problem is removal! How do I get glued down hdwd off of an OSB subfloor?....installer did not use underlayment. I popped up two small pieces of hdwd and the OSB peels up leaving a rough surface. Do I have to remove the subfloor?? Can the new B. Cherry go over the old wood if I address the wet spot??(cut out and patch?)

OSB?
Depending on the OSB Quality, you can nail to it if not water damaged.

If water damaged, you will need to remove and replace the damaged areas.

OSB is approved for nail down of solid wood floors, but I would do a test area and see how strong the nailing/stapling holds before installing the entire area.

thanks but any ideas on the removal of the hdwd??
With the rough surface after I pry up the old hdwd I fear the new will not have the appropriate flat level surface. A collegue of mine mentioned with OSB that the layer that comes off with my removal isn't likely to cause too much of an issue? Any thoughts?

If it is a good glue down alot of your subfloor is going to come with it unfortunatley. If you can get it up with minimal damage you should be able to resheet it with a substrate (1/4-1/2) plywood. Other option is to remove both the floor and subfloor. Both arer costly, and time consuming. An unfortunate situation for you.

I wouldnt recomend installing another floor over your existing flooring.