From Sahih Bukhari (Hadith 2522):
Narrated `Abdullah bin `Umar:Allah's Messenger (ﷺ) said, "Whoever frees his share of a common slave and he has sufficient money to free him completely, should let its price be estimated by a just man and give his partners the price of their shares and manumit the slave; otherwise (i.e. if he has not sufficient money) he manumits the slave partially
Reference: Bukhari 2522