how do I remove the ecm?

What is your question?

engine idles at 1500 - 2000 rpm all the time even after it is warmed up fully. It also surges (or jerks along under load especially at lower rpm's. The mileage has dropped considerably and I usually smell gas when it is idling. On the rare occasion it will idle down and run properly but never for very long. I have had the map sensor, the mass sensor the engine temp sensor all changed. The ambient air temp reads the outside air temp properly and I have been told that the ecm is likely faulty? Any ideas?

How long has your 1997 Suzuki Sidekick had this problem?

two or three years.