Sync Live Changes of NopCommerce with local

Hi, my client has installed nopcommerce on smarter hosting account, he has installed custom theme and making some further changes, I have download latest nopcommerce and making some changes related to some custom functionality, can you tell us how we will sync our changes? he is working on live through back end admin panel and I am working on local doing some coding changes

A similar question has been answered here. Have a view! Thanks