Gas and Oil Home Heating Furnaces - Removing A Radiator

I'm remodeling a small room in our home. It has a small radiator on a non-load bearing wall therfore, the wall had saged a bit. I have no problem with the repair of the wall but, I'm going to remove the radiator and replace it with a hot water base board type. I see that this has been done in other parts of the house. I know how to bleed system and all that from info I got from this forum.
This is a hot water system, not steam

Questiion is: I have access to the pipes below the Radiator and was loking at them. I think taking apart the fittings to install a reducer to switch to copper is going to be tough.
What is the best way to loosen th fitting without cutting or breaking them?

You dont say for sure what you have here. You can put WD 40 on it. Then take a large hammer hold it on one side of the fitting. With a smaller hammer tap on the other side of the fitting and go around the fitting this way. You can use a torch and heat up the outside of the fitting some. Or just get bigger pipe wrenchs;) ED

Thanks for the reply.

I just need to break loose the fitting and I'll try the WD40 thing but, it looks like the years have made the pipe in to one piece instead of two! LOL If I break the pipe, then what? Plumber time? ;)

Like I said you didnt say just what you had there. If its a cast L and you break it Ok take it off and chase the male threads on the old pipe and put your copper on it. But try the hammer's on it not to hard .;) ED