How do I go about licensing a patent?

You need to develop a licensing strategy, taking into account what resources you have and the target licensed companies you want to engage. If you have targets that are already interested in licensing your patent, then the rest is easy. You would get an experienced licensing attorney who would assist you in negotiating the licenses and preparing the contracts. If you do not have target licensees, then the task is more difficult. You will need to prepare written or oral presentations to present to the companies that you believe need a license and show them why that is the case. Again, you would need to engage a licensing attorney experienced in this kind of work.