I changed the schedule about English telephon study yesterday

->I changed the schedule of my English telephone class yesterday.

I want to study English at home after leave the office

->I want to study English at home after leaving the office.

Home is comfortable to study then Office

->Home is a more comfortable place to study than the office.

->It's more comfortable to study at home than in the office.

Office is not concentration to study with many minor things

->In the office, you can't have concentration in studying because of several minor things that can destruct you.