Tips for oil changes:
They should be done hot. It gets the contaminants in suspension and makes it easier to drain.
You don't need to drain any oil coolers or lines, as long as you do regular oil changes. The additives in the new oil will clean out the system, and there's so little of the old oil, that it's inconsequential. If you are changing every 50 hours anyways or every annual, your oil will still have a little bit of useful life left (oil can get REALLY REALLY nasty before it's considered "bad").
This is really, really useful for oil changes:
http://www.aircraft-tool.com/shop/detail.aspx?PRODUCT_ID=18611 . For those using rotax engines, they do have a small size.
Punching holes in the filter: do it carefully if you intend to inspect the filter for chips. You don't want to do an overhaul because you found chips from the oil filter do you?