Remember I`m talking about a 135, but very straight forward - a socket with a 100mm extension - easy peasy - however having said that - I was luck the bolts weren`t seized.
The only complication was the run of flexible exhaust pipe from the elbow to the muffler - mine is only short (on the port engine ) and took some effort to firstly break the rubber pipe free from the elbow WD40 helped), then get it to bend enough to get the elbow free.
I took it off, more out of curiosity than anything - I had steam from that engine and found the impellor was stuffed - I know the heat exchanges are good so I thought I`d check the elbow - glad I did - it was made of mild steel and had rusted on the inside - enough that when I poked a wire down into the cavity between the inner and outer pipes to clean out some gunk - it broke through the weld, letting water into the exhaust. Raw steel and salt water aren`t great partners. That's why I had mine remade in stainless. The other side is next.
IG 36 Europa