Yes, welcome to NICO. I can't say I have seen much documentation on your particular swap. The current generation Frontier is still new and doesn't seem to be as mod-friendly as previous Nissan trucks. That's changing everyday though as Frontiers come down in price. There is lots of engine swap information in general available all over NICO. Most swaps have a lot of things in common. It's best to have a donor car but if one isn't available you will need to gather not only the engine, computer and wiring harness; you may also need to procure a transmission in case the 2.5L transmission doesn't bolt to the 4.0L. Sensors, pins and terminals will also need to be collected. NICO has a very respectable collection of Factory Service Manuals at
www.nicoclub.com/FSM
NICO also has a tuning forum which may help you with your ECM swap.
Take pics and leave notes so others can learn from you experience.