Was Congo renamed after gaining independence

Yes, Congo was renamed after gaining independence from Belgium in 1960. The country was originally known as the Belgian Congo and was renamed the Republic of the Congo following independence.

Which colonizer gave independence to Congo and who was the prime Minister/president of the colonizer at that time?

Belgium granted independence to the Republic of the Congo in 1960. At that time, the Prime Minister of Belgium was Gaston Eyskens and the King of Belgium was Baudouin I.

Who was the Nationalist leader and what was the political party called

The nationalist leader of the independence movement in the Republic of the Congo was Patrice Lumumba. He was a key figure in the struggle for Congolese independence and was a leading member of the Mouvement National Congolais (MNC), which was the political party that played a prominent role in the movement for independence. Lumumba later became the first Prime Minister of the newly independent Republic of the Congo.

Who was the first PM/president of republic of Congo and when did it gain Independence from Belgium?

The first Prime Minister and later President of the Republic of the Congo was Patrice Lumumba. The Republic of the Congo gained independence from Belgium on June 30, 1960. Lumumba became Prime Minister shortly after independence and then later became President, but his time in power was short-lived as he was overthrown and subsequently assassinated in 1961.

What method was used to gain independence: arm-resustance, negotiations, external pressure or colonial power wish to leave?

The Republic of the Congo gained independence through negotiations with the colonial power, Belgium. There was not a significant armed resistance movement in the Congo leading up to independence, and the process was primarily driven by diplomatic negotiations between Congolese leaders, including Patrice Lumumba, and Belgian authorities. External pressure from other countries and international bodies, as well as the desire of the colonial power to grant independence, also played a role in the decolonization process.