CentOS 7.x

yum remove git
yum install epel-release 
yum install https://centos7.iuscommunity.org/ius-release.rpm
yum install git2u

CentOS 6.x

yum remove git
yum install epel-release
yum install https://centos6.iuscommunity.org/ius-release.rpm
yum install git2u