You can soak it in rubbing alcohol multiple times. This will take a while because you're only going to take the sap off layer by miniscule layer. Once you've got it nearly gone you should be able to wipe it off with a good detail spray. Make sure you re-wax the entire area around it where the alcohol touched the paint.
If you want to clay bar the entire car that should work to but even a claybar may have some problems pulling that up. And I don't like using an entire claybar or even half a bar on one spot. Besides, you really want to loosen the bond it has formed with your paint. A strong clay bar might just rip it right off the paint but what's stuck to the bottom of the sap that might be coming off with it?
Wash the area with liquid ultra dawn dish soap with a microfiber cloth it won't hurt the paint like the alcohol. Then Clay bar the area wash with your normal car wash soap follow up with your normal wax or polish! if sap is in different areas wash entire car with dawn dish soap and you should clay the entire car! Better for car Best for paint!! It will remove all contaminants then follow that up with your favorite wax or polish! Me? I use Zaino products and really don't have to worry if sap gets on my car! I comes right off! It Amazing Stuff!