Was also going to post this link. (Barry beat me to it.)
Pay special attention to the last post by TIG, which explain a non-explode way.
(But you’ll still need to do the property and attribute copying part. Then erase the cinstance, a lastly the definition purge.)
Here’s another related topic:
Move all entities to new group
This is butt-backward to what he wants.
And at one time this method (to_component) was bugged in that it dropped all the attribute dictionaries (perhaps other properties.) Was it ever fixed ?