2001 Windstar needs replace computer ECM

I have a 2001 windstar that I need to replace the ECM computer...What is required to do this.Can I just remove and replace it?.I can get another one very close to part #'s and model and series and version..I am getting different stories that I have to get it flashed at the dealer.. And the chip in the key has to be reprogrammed..and the Vin has to be changed and so on.It doesnt look like the key is that type.Once I do put the new ECM in I am afraid the car won't start because of the key issue..Do I limp it to the dealer change with the replacement ECM and then they can do what they have to? Thank You in advance for anyone that has some insight to this..

Did you get a disgnosis to replace to ECM and what are the causes of this replacement proposal? It is very rare that the ECM has to be replaced, however many systems can fail and make the ECM not acting properly.

I am unable to read the OBD II connector..The service station said it needs to be replaced..The vehicle is acting very eratic..Engine codes pop up constantly..If I take my scanner tool and try to read it the engine light goes out and tells me "unable to link" then I disconnect it and then engine light comes back on..Very frustrating....I am gettiing a new ECM by Friday and was wondering how involved it was to replace it...I appriciate your response..