Run towards your designated wall according to the blocking. And just jump onto it as if the wall was going to catch you. The rest of the time you will probably just run offstage.
Really, I wouldn't worry about it. You won't have to do the trick at all. And the funnier you make the fall, the better. (If that is what the director wants.)
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle