how make parent blueprint for existing blueprint?

I have blueprint actor, me need make him child from another blueprint whom iam make after him. Me need add parent for blueprint.

Simplest way is just to create a child blueprint and then copy paste the stuff you want in there. Unless you have a really complicated blueprint this usually isn’t too tough. There is a way to change the parent of a blueprint though if you check the top right corner you can see it’s parent. I have had mixed results with this in the past though.

Copy past is a bad variant

You can reparent a blueprint. Open your blueprint : In menu “file” : reparent blueprint.
You’ll have access to all inherited variables (you have to click on “show inherited variables” in the eye on the top left of “my blueprint” if you don’t see them)
Set what you need in parent in event graph or construction script in a function and call this function (beware the function is still in parent) in your child.
Add parent functions by calling them : on a red event or construction script start : right click : add call to parent function.