What do you mean by guide? The service manual?
I’m pretty sure this site has all the service manuals available I have seen people post the links. But I have never looked myself
Are you having trouble with the plug or the actual ecu is stuck? All that holds them in is those rubber bumper things into the metal tabs. You can slide the ecu out of the rubber or pull the rubber off the taps. If you can’t get the rubber to push over the metal tabs use a little lubricant spray on it. Maybe it’s just gotten old and stiff. But it should pull off those metal tabs. Maybe get it started with a little plastic pry bar. Or go full gorilla and use a screw driver.