Sheikh bin Baz رحمه الله mentioned that even laypeople can do Takfeer in certain cases. Question: Can laypeople or even do they have to Takfeer a person who rejects the Sunnah as a whole, despite being shown the evidence for it being revelation. (The person knows arabic)

Ustadh AbdulAziz al-Haqqan

Allah did not hold your responsible for making takfeer of people by name. There are judges and muftis that can look into these cases and determine whether they meet the conditions or not.