Two relatives are the same person

I am new to this site and still trying get use to how it works. I was adding my Grandfather the other day His name is William Don Evans 1932–Living • G829-3MX. I was looking on the left at the Research Help section and I accidently click Attach to a record that looked like his. I didn't noticed until after that it had him as deceased. Now I can't get the person with the wrong info showing up in my tree. It shows him as my Granduncle. Here is the wrong info. William Donald Evans 1 June 1932 – Deceased  • G4Z3-6P1. How do I remove that person from showing up in my tree. Thanks.