You cannot have a "real" change, a "real" revolution, without spilling some blood.
A system of monarchs, with kings supposed to be descendants from gods, thousands of years old, spread all over the world, in each and every country, was brought to an end by French people. If this can be done, ousting some bunch of corrupt leaders with no special support from majority of people can be done quite easily. Nepalese just need to grow some French balls , bring the guillotines, and let the blood flow in "khulla-manch".