From Sahih Bukhari (Hadith 2503):
Narrated Ibn `Umar:The Prophet (ﷺ) said, "Whoever manumits his share of a jointly possessed slave, it is imperative on him to manumit the slave completely if he has sufficient money to pay the rest of its price which is to be estimated justly. He should pay his partners their shares and release him (the freed one)
Reference: Bukhari 2503