Simplify the following text for a Grade 10 native English-speaking person.
Original: Then , along with more than three hundred Chinese citizens , he signed Charter 08 , a manifesto released on the 60th anniversary of the adoption of the Universal Declaration of Human Rights ( 10 December 2008 ) , written in the style of the Czechoslovak Charter 77 calling for more freedom of expression , human rights , more democratic elections , for privatizing state enterprises and land and for economic liberalism .
Simplified: It was released on the 60th anniversary of the adoption of the Universal Declaration of Human Rights ( 10 December 2008 ) . They wrote it in the style of the Czechoslovak Charter 77 calling for greater freedom of expression , human rights , and free elections .