I have embraced Islam. The Prophet ﷺ said to him: Remove from yourself the hair that grew during of unbelief, saying "shave them". He further says that another person (other than the grandfather of 'Uthaim) reported to him that the Prophet ﷺ said to another person who accompanied him: Remove from yourself the hair that grew during the period of unbelief and get yourself circumcised. (Using translation from Abū Dāʾūd 356)  

أَنَّهُ جَاءَ النَّبِيَّ ﷺ فَقَالَ قَدْ أَسْلَمْتُ فَقَالَ أَلْقِ عَنْكَ شَعَرَ الْكُفْرِ يَقُولُ احْلِقْ قَالَ وَأَخْبَرَنِي آخَرُ مَعَهُ أَنَّ النَّبِيَّ ﷺ قَالَ لِآخَرَ أَلْقِ عَنْكَ شَعَرَ الْكُفْرِ وَاخْتَتِنْ