What is world 1 skip?

How do you reset your progress for the intention of a speedrun?

World 1 Skip is a skip which allows you to skip the first level entirely by leaving the current world, I just wrote a little guide for more informations: http://www.speedrun.com/Woodle_Tree_Adventures/guide/rkd2e

For a game reset, please check out this guide: http://www.speedrun.com/Woodle_Tree_Adventures/guide/5uc0v

How do you perform that Clip thru the Wall in w2?