How can I change pw and access my web server instance?

Hi forum friends, I am a content developer and my web developer decided to no longer support my web server instance on AWS EC2. I have a basic plan n AWS so no hands-on tech support is available. However, in lieu of upgrading my plan is there an easy way to: change the password on my web server instance? I want to gain access for myself and whomever I hire to be my next web developer. Thanks for yuor responses in advance.
Best,
Jeff