Dell Inspiron 1500: Forgot Sign-on Password After 5+ Years

I have a Dell Inspiron 1500 laptop that hasn't been used in over 5 years. I've forgotten the sign-on password and can't access the system. I've checked iFixit's guides, but couldn't find a specific solution for password removal on this model. What are the recommended steps to regain access to the laptop, considering it's been unused for so long?