is it the same amount of work to replace the two o-rings?

thank you.[/QUOTE]

It is only one bolt that holds the oil lines into the thermostat housing. It is the easiest one to get to. Once the bolt is out the lines are easily disconnected. A mirror could let you see it. It would take removing the fan, belt, and alternator to get to it I believe. The o-rings should be replaced at the same time as that gasket. It is still mostly a blind job. If you could confirm the o-rings were the source of the leak I think you would have an argument for them to replace them.