The oil will drain more quickly and completely if the engine has been warmed up for a few minutes and left for 3-5 minutes to settle. Assuming you have removed the fairings for an engine removal, you’ll find the sump drain bolt on the front of the motor at the bottom:
Grab a socket – a 13mm one will do. Be very careful of the exhaust if you have warmed up the bike first! Place the drain pan under the engine, then crack the bolt:
…undoing it the rest of the way – be careful not to drop it into the oil pan!
There should be a crush washer under here, but it looks like someone has replaced that with some silicon. Best to use the crush washer, it should be below $1 from your Triumph dealer.
Put the sump plug back in – partially to stop more oil dripping out, and partially to stop anything else from getting in.
To be continued…