I used to teach this specific excercise until I retired last year. Our sims would reposition to 12NM, 2000ft and obviously I could set VMO.
I suggested A/T out initially to avoid unwanted thrust inputs and initially avoid the need to use the speed bug.
The key is in the handling, avoiding any descent until gear and some flap achieved.
So at your gate:
1. Thrust idle and speedbrakes out
2. Level or slight climb.
3. U/C down on limit.
4. Flaps to 30 when passing flap 1 speed, let load relief do the job.
5. If you have an ILS, use it and plan an autoland. So intercept the glide.
6. Set speed bug to F30 +5 and re-engage A/T.
7. Speed brake in as flags pass 20 to avoid warnings.
8. Established, Engage AP for autoland.
If done well you will be fully established by 5 NM.
This is how I would demo it but for me the gate would have been 10NM 50 -80 tons above MLWt and a bit closer if light.
As a sim instructor you can demo this easily standing behind just by commanding the crew to select services. With the quick reposition to 12 NM / 2000ft the whole thing can then be practiced by both pilots in a few minutes.
Probably the most important item though is that to get to your gate, in a smoke situation, one pilot must exclusively fly with the other running the ECL without being monitored, otherwise you run out of time to get the important bits of the Smoke checklist done, even from cruise level at 80 NMish
Try to get back together below 10000 and just run the normal ECL checks, they will pick up the important things you have missed.
If there are any slight errors in the above, apologies I retired 18 months ago.
This really is a crew excercise but not in the normal sense, you must know when to work on your own and when what your colleague is doing is critical and he/she needs your support.
I do know of one 747 cargo outfit who practiced this every sim check, their gate was 10NM / 2000ft / VMO. I found out that the 777 is just the same, 200 through to 300ER.
Hope this helps.