Sometimes parts print best without supports. These parts tend to be much thicker than the ~1mm base generated with the support structure, which causes them to adhere very strongly to the build platform. When I’m having trouble removing the part from the build platform, or if I’m worried about breaking the part from scraping too hard, I’ll spray some IPA around the part and wait ten minutes. The alcohol makes removing the part quite a bit easier. Happy printing!
When the going get tough, I also like to turn the build platform on its side and rest on side on the finishing tray. That way, I can push down with the scraper without having to support the platform–and the part will just pop off the side. Much easier than trying to go after it from the side while you’re holding the platform.
We found that a razor scraper can be helpful to get stubborn parts started. Then thicker blade of the putty knife can get under the part more easily. You can pick up a razor scraper in the paint department of a hardware store.
I usually try to pry the corner of the scraper under a corner of the platform, and wiggle a bit. repeat on the other corners, and then slide. With the latest material updates however I found the support base really easy to remove, so that problem is not really a problem anymore.