Copying an existing website from Typo3 to Joomla

Hello A website existing in Typo3 needs to be copied into Joomla(done form scratch in Joomla). Me and my colleagues should be able to change content as easy as possible on the site, possible through the front end. New pictures, news stories and pdf files will be posted on a regular basis. Beside copying content over it also involves setting up a joomla template after the old layout. Thank you.