How to turn objects into prefabs?

I made the huge bonehead mistake of not reading the unity docs BEFORE I started on my project and I learned about prefabs after I had aleady been just copying and pasting objects. Now I want to know if there is a way for me to replace objects with prefabs but keep their transform position. What I want to do is turn all of my identical(not prefab) objects into instances of a prefab. Is there an easy way to do this?

In project view, right click → Create → Prefab and from Hierarchy view just drag and drop the objects into the Prefabs.
You can drag the same objects into the Prefabs and click on Replace anyway, t will turn both objects into the same prefab and yuo can apply a change to the prefab and it will aply the chanage to both objects,

I ended up using the forum link. The link is right here: http://forum.unity3d.com/threads/replace-game-object-with-prefab.24311/

it worked really well for me although I assume TRG96’s answer would work too. Thanks both of you!