@Meko Guy Wow, you can't get it? Spoiler Timing isn't too bad if you put R back in his starting direction after executing the first move
@Azza - Yes - I was doing that but releasing R and holding P for R to mount is the problem. They both tend to freeze and release at the same time. Another issue is, if P is turning as R mounts, R will not get off at the win if R makes it to the win. You also said 'no tricks' and I'm pretty sure you have a R auto pilot (walking down stairs - move stairs - P falls). The R long legs at the stairs, raise lift and R's leg shorten is also a trick even though it's R behavior. I got lucky on the mount...
@Meko Guy Well, the R behaviour I can hardly help, but that autopilot... You have to wait until P is on the horizontal draggable, then move it. Then P falls. Is that a trick?
@Azza - If you drop R with the stairs (hit) then no trick but I found R would end up on the stairs as you need to freeze R (continue to hold the draggable) so I moved the slider as R came down. Many players would say that all R moves are behaviour ones but I disagree. If you need to do something, like raise the lift so R's legs shorten then lower that starts into the tricks for me.
Seeing the above discussion made me realise i was missing something as i was unable to reliably freeze P after the autopilot and i just relied on timing instead. Enjoyable puzzle.