Dear sir, please contact me, we'll discuss about your requirements. First I'll copy thesite1 and install it temp hosting with domain thesite2, for you to check when it work good, I'll copy the site2 and install it in temp hosting with domain thesite1 for you to check, when it work good, I'll copy it to main hosting. The final thing is copy users data from site 1 to site 2 (or site 2 to site 1).