Is this possible what would have to be done would I only need to swap motor or would it need a new transmission as well if so how much would this cost to do I have access to all the tools and equipment required

 

The computers are different. You'll have to get that wired up to work with the car in some way, they're not directly plug and play, and especially not Crown Vic to Mustang.

The transmission may can get away with a 4.6 bell housing if there's one available, as the thing should be an EAOD, I believe? Unless you have a manual, in which case, again, bell housing.

And a litany of other things that I'm not gonna chase down for a 3.6L Mustang. I'll find a GT first.

It's not impossible... but there's plenty of write ups via any search engine regarding any number of swaps on the SN95s, and all of them to a one have this or that or a bunch of issues that were unforseen... except a direct correct engine swap.

But you can do it! I believe in ya! And welcome to the forums!