Baritone ukulele tuning uses the same procedure you use for tuning the four smallest strings of a guitar.
There are many different types of ukuleles, but the four main classes are: soprano, concert (alto), tenor, and baritone. The baritone ukulele is the largest of all these ukuleles and is the one most similar to the guitar. If you love to play the guitar, you will find it easy to switch over to the baritone ukulele.
The standard tuning arrangement for most ukuleles is the G-C-E-A arrangement. You can use this and tune your baritone ukulele to this arrangement, but a couple of things might happen. The increase in the string tension might cause the neck of the instrument to bow or you might break the bridge off the ukulele. Either way, this arrangement is possible to do, but many people prefer to tune their baritone ukulele to the D-G-B-E arrangement. It provides a richer, fuller, sound. This is also similar to the top four strings of your guitar.
Once you know your arrangement, you can identify which string goes to which peg tuner. Then you will have to either tighten or loosen the peg in order for it to hit the right note. This is something that most people who play the guitar are very familiar with. It will be no different than tuning the top four strings of your guitar.
If you have not played the guitar and want to learn to play the ukulele, you can learn how to tune and play it by going online to websites that have audio clips of how the baritone ukulele should sound once it is tuned correctly. You can study the tips on how to tune a ukulele until your instrument begins to sound similar to the audio clips.
This will take a bit of trial and error. You will start with the top string and work your way down. Then, you will have to come back to the top and see if any of the pegs have tightened or loosened, changing the overall sound. After going down the strings several times, you can set it aside and see if the strings settle later. If this is too nerve-wracking for you, you might be able to take it to a music shop where they can do the proper baritone ukulele tuning for you.