Obtain a guitar. If you don't have one, you can buy one at any musical instrument store or online. You can also rent instruments through musical instrument stores or even some schools. You might even find one at your local pawn shop, which can often have a variety of musical instruments for sale at reduced rates.
Purchase guitar lessons or DVDs that teach how to play guitar. Like any instrument, you need to learn basic skills. You do not need to be an expert to play "Yakety Axe," but you should know fundamental guitar handling.
Seek specific websites that are designed to teach musicians how to play specific songs, especially if you are new to guitar playing. An example would be 911tabs.com. On this site, you can find videos created to teach interested guitarists of all levels how to play this song.
Obtain the music and lyrics to "Yakety Axe." You can find this at any store that sells sheet music. Most stores can order it for you if they don't have it in stock. Guitar tablature (the music and lyrics) can also be found at many online sites. One of these is tabrobot.com. It searches more than 850,000 tabs. It can find almost any popular song tablature for you and does contain various versions of "Yakety Axe."
Practice regularly. Guitar playing is an acquired skill. Give yourself a break if you don't sound like Chet Atkins right away. If you keep trying and persevering, one day "Yakety Axe" may be an important part of your musical repertoire.