Steps on how to turn a gay guy straight?

People are attracted to whom they are attracted to.

It is not possible to change a person's sexual orientation. The only thing close to what you're about would be to discover that they are, in part, bisexual, which would be a pre-existing component of their sexual preference, not something with which they could be instilled by anybody who happens to want to change them. Also, you can't make somebody start liking girls, or stop liking guys at your whim or fancy. It just doesn't happen.

So the answer to your question , in brief, is that it's impossible. You can't do it. It is completely beyond any level of plausibility. If you want proof, go ahead and try to change your own sexual orientation. See how much success you have.