Site Down, How to Resurrect?

Recently I was working on a website and did a lot of custom PHP and CSS and completed the site for a colleague, using his login details. So Later on he logged in and turned it upside down by messing with PHP. Now we cant even log in!

Luckily I download some backups using updraftplus. The issue is that both of us dont have cpanel access. So the only option is to upload to a different domain name. But how?

I have the original php and the DB, What changes do I make so that I can upload it to a different domain name and continue developing it?