Who helped Mandela to stop apartheid law?

As well as the ANC leader Nelson Mandela, the South African president F.W. de Klerk was also instrumental in bringing apartheid to an end.
Thanks to apartheid, South Africa had been turned into an international pariah state. A number of white politicians such as de Klerk realized that the situation could not continue and began to contemplate dismantling the system of racial oppression that had dominated South African public life for over forty years. De Klerk's party, the National Party (NP), had introduced apartheid in 1948, but there was a growing sense among the party leadership that the policy was untenable, not least because of sustained pressure for change from the international community.
Through a number of important steps, de Klerk gradually dismantled apartheid, setting South Africa on the road to black majority rule. In 1990 he lifted the ban on the ANC; not long afterwards, he authorized the release of Nelson Mandela from prison after 27 years of confinement. There then began a series of formal negotiations between de Klerk and the ANC leadership to end apartheid once and for all and to bring about a peaceful transition to democratic rule.