Tub spout question/identification

[Lildiy]

This may be dumb to ask but I've searched all over and can't find what I need.

We needed to replace the spout in a tub/shower and couldn't get it free; someone came to help but couldn't get it either. They then used a hacksaw to remove the plastic-like spout, breaking it off and leaving behind this [pictured].

They said they've never seen it before and said they were going to talk to someone. They came back and said that they were told it was some sort of special hookup that requires some pressure setup and it connects with hoses, which requires us to hire a professional to do or it could damage everything.
This didn't seem right, but we haven't done a lot of diy plumbing ourselves.

After looking around I found a picture [also attached] that looked similar to the piece left behind. My question, if anyone can help, is if this is some special job we shouldn't touch or if it is in fact just the diverter/wall end attaching piece?
*Not sure of proper terms...

Any help or suggestions are greatly appreciated!

 

[Stuff]

Use a knife to cut the caulking securing it to the tile wall and then it should unscrew.

 

[Sponsor]

 

[Terry]

I think you nailed it.
It's fits to either a 1/2" pipe nipple, or a 3/4" pipe nipple. Most likely 1/2"
So...........a diverter spout that fits with a 1/2" pipe thread is the best guess. Go ahead and spin off what you have.
Good research by the way.