Yeah Daniel, it's not a big deal fixing the trunnion, hell if I could do it on nearly every tractor I own, it'll be a breeze

for you.
As mentioned, the amount of heat your going to use to close up the corners isn't a big deal, but for the "just in case" wrap a wet rag around the shaft and over the pump. You'll be golden

Oh yeah, take it from the expert, (me) do not clean out the differential with paper towel on a hydro either, it's to easy to not get every piece out, and the pickup tube frowns on that

Jon will get a laugh out of that