While scholars try to portray a confrontational relationship between Buddhism and Hinduism, many facts point to the fact that they just co-existed. The book I am reading, Massacre at the Palace: The Doomed Royal Dynasty of Nepal has some information on the relations between Hindus and Buddhists in Nepal.
The Newars of Nepal developed a kind of Buddhism quite different from that practiced elsewhere. As Buddhists they were allowed to eat meat including buffalo and the pig. The Newars could have a Brahmin as a priest and Hindus would worship in Buddhist shrines. The Shiva temple at Pashupathinath has a strict prohibition on entry by non-Hindus, but Newars are allowed to enter.
There is a festival of the Hindus involving a Kumari, who is considered a living godess. In Indrajatra, she is pulled on a chariot through various parts of Kathmandu and she gives blessings to the King who is considered a partial reincarnation of Vishnu. This Kumari who features prominently in the Hindu festival is chosen from the Buddhist priestly clan of Sakyas (the same clan as Buddha).