What error message do you get? I recently got an Error 53 (I think) every time I tried to delete any file and had to do a clean install. That happened after I messed around with Disk Utility and Paragon to create EXT4 and FAT partitions for installing Linux without an external drive. The permissions got damaged and I couldn't fix it without re-formatting everything.
I have no problem deleting those two folders in the Finder. I tried it before my first post and only got asked for my password. SIP is always disabled on my Mac.
Edit: You could try "First Aid" in Disk Utility to repair the permissions, otherwise the "Root User" should be able to delete EVERYTHING....