1) Gain support and funds from foreign occupiers. Murder the prime minister for being hostile to your benefactors 2) Start a war with another nation; while many of the people will give you support, many more will blame you for the devastation you caused. This is a good thing as it makes you more relevant. 3) Clash and kill local soldiers for veto power at the parliament. 4) Threaten a coup unless the investigation into the murder of the PM is ceased. 5) Topple the government and take over.
Saudi-led planes hit Houthi-controlled government buildings (Reuters)
from the article: Hezbollah-backed Najib Mikati tapped as new Prime Minister of Lebanon