So you don't have enough money to buy an IR transmitter? That might make a project that needs to send IR commands a bit difficult.
Or are you planning on hacking your remote control?
As far as telling you how to do it, sure...
First, you plan out what you need it to do. You then gather the necessary parts, hook them up and test them individually. At that point you can start writing the code, testing,and debugging until you get a fully functioning project.