How to put yourself behind someone else in a movie

Hi, Can you replace an actor with yourself behind another actor in a movie using DaVinci Resolve? I have searched Youtube for tutorials but couldn't find one. Can DaVinci Resolve do the Forrest Gump method? i know other video editors can do this, but I wanted to work with Davinci Resolve and hope that it can also do this. I appreciate any help you can give me with this, Thank you. Mandy

If you don’t have both in front of a greenscreen, it’ll be tedious Roto work.
I’d recommend Mocha Pro for that – or a lot of patience.

Yeah, you can do it ... but as Uli pointing out it's going to be a lot of rotoscoping (masking) work, so I hope for you that the sequence is short.

You will basically isolate the foreground and background manually, frame by frame, using masks.
And if the new subject you're trying to paint doesn't cover the old one, you'll also need to re-paint missing background pieces ( either from clone, or clean plate or ...).

There are tons of variations in the process depending on the exact case / footage.

And if you’ve got the money, Silhouette is the best tool.