See run brick above first!
Race simulation - start out easy and at the start of hour 2 you should be in high Zone 2, the last 30' are Zone 3. Go right into the brick.
WU: Run 9k warm up BEFORE bike
MS: AFTER bike, run the same 9k: 3k moderate effort, 3k hard effort, and then 3k very hard effort.
CD: At least 10' of walking easy.
WU: 300 warm up and swim 8 x 50 on 20" rest.
MS: 100/200/300/400/500/500 all with 10-20” rest. Last 500 should be ~3-5” faster per 100, than goal 1/2IM Pace.
For example, if the goal is 0:30 swim at 1/2IM - that would be 1:25/per 100/yd pace. So, the goal in the last 500 of this 2k set would be under 6:50 or 1:20-1:23 pace.
CD: Get a nice easy 300 cool down.