Short answers, pulled from the story.
Micipsa left his kingdom to two sons Adherbal and Hiempsal I along with their illegitimate nephew Jugurtha. This arrangement fractured immediately after Micipsa's death when Jugurtha moved to eliminate his rivals.
The Senate refused to honor this capitulation after Spurius Postumius Albinus failed to act energetically against Jugurtha in 112 BC. His brother Aulus Postumius Albinus marched into the Sahara desert in mid-winter where half the army was killed before survivors passed under a yoke as a symbol of surrender.
Gaius Marius arrived in Numidia as consul in 107 BC and exempted property requirements so poor Romans could serve in the legions. He marched west plundering countryside and seizing minor fortresses while executing all survivors at Capsa after the town surrendered.
Lucius Cornelius Sulla served as quaestor under Marius and negotiated with Bocchus to receive Jugurtha as a political hostage. Sulla entered Bocchus' camp despite risks of treachery on the Mauritanian's part until Jugurtha's remaining followers were massacred by Bocchus who then handed over the king in chains.
Jugurtha was thrown into the Tullianum underground prison in Rome and executed after appearing in Marius's triumph in 104 BC. This event marked the end of the conflict which exposed deep corruption within Roman politics from 111 to 105 BC.