Yell "Get off the trolley tracks! There's a runaway trolley heading directly towards you!" at the five people.
This is a bad idea. A very bad idea.
Consider the logical consequences.
Those 5 people will get out of the way. But then they'll see you. Standing there, gormlessly, by the lever.
There's no getting out of this. You can't play dumb, after all, you just verbally confirmed to everyone present that you
knew about the trolley and you
knew it was coming for them.
And they'll wonder: why didn't they just pull the lever? Why subject them to the fear of momentary death by trolley when they could've stopped it with a single pull?
The hatred will fester. Over generations.
And one day, when you're standing down the streetlights of an incoming trolley? They'll remember. And they'll act accordingly.
We need to preserve our own safety above all else. Because who else can be trusted to behave the most altruistically?