Deploy .net site to https root domain from nonhttps subdomain

I had this project completed about 97% initially and wanted rest of it done. Freelancer 1: Made it to about 99% and deployed site to https root domain from http subdomain without any issue. Then he had to leave to Europe. So, I hired Freelancer 2 for rest of the work: He made it to 99.9% complete but failing to deploy to https root domain. It works fine in http subdomain. So there is something that freelancer 2 is unable to get. It could be related to issues with http to https, I do not know. Since Freelancer 1 was able to deploy properly to https subdomain, this is definitely possible. I have source code and website files of all versions. So, now I want someone to deploy it properly to the https root domain, and also perhaps if you are an expert in .net, fine tune some things here and there (will let you know after). Currently, the main task is to deploy the site. If you are good with deploying sites, apply.