How to teach my horse how to change leads?

ok, so im not riding yet cause he's too young, but this spring i am going to, so i am going to teach him barrels but everybody says you have to teach him to change leads, is this a necessity or just preferred? and id like to know how to anyways, so step by step instruction? im up for a challenge!! :)How to teach my horse how to change leads?
I ride mostly English (western every now and then) so I'm not as familiar with western cues but I can give you some tips that I know work for both disciplines. First, you want to make sure that your horse is balanced and stabilized. When asking for lead changes, balance truly is key, and can help them get their leads more naturally with out us confusing them with cues. You might also want to start doing simple changes before you get into flying changes. When teaching simple changes, I usually do a figure eight and when you get turn to change directions, break into a trot (or jog I guess for western lol) and then go back into the canter when you're going in the new direction. Each time you do a simple change, shorten the amount of time that you trot in between your canter transition. The cues for a lead change in English are to put your weight in the outside stirrup and pick up your inside rein a bit. I'm pretty sure it's the same for western but you may want to double check just to be sure that you aren't going to confuse you or your horse. Good luck and hope this helps! :-)How to teach my horse how to change leads?
I think that your horse does have to change leads when running barrels, but more than likely they just change leads as you go, but if he dosent there is a few options:

-Just work with him on the rail

-Wait until you get into the corner of the arena to ask for the transition

-When he/she gets on the right lead praise him a lot

I had the same problem with my horse. Horses are very smart animals and if you keep working at it, he/she will catch on.
i have herd that when they are on their right lead they can go faster and stop easier... i would just work with him on the rail for a while you cant teach a horse to do barrels intill they are fully trained... just train him teach him the right leads on the rail and then after he is all the way trained teach him barrels that way he will know every thing and he will know how to change leads and everything.... i hope this helps and good luck training him