You can send it back and they will do the upgrades. Of course there will be a charge for the upgrades and rewiring. Email Ultrasabers 1st. They can give you a list of upgrades and prices. Plus tell you how to go about the entire process. Start with the email.
Yes, this is exactly what you need to do. Tell them the saber you have, and exactly what upgrades you want, and they will reply with a line-item price list (or at least, they did with me). They will then outline the steps you need to take to make that happen. Note that it would have been cheaper to order exactly what you wanted the first time, but if you’re like me, you didn’t know you wanted all that stuff until you had the saber in your hands and had gotten a chance to examine it closely and use it for a while.
After you get the cost estimate, compare that to the price of ordering another complete saber that has all the upgrades you want, and you just might find, like I did, that the relatively small difference in price could make purchasing a second saber the better choice. After all, if you need to spend $Chunk-of-change to get your saber upgraded, and you can spend $Chunk-of-change plus $Small-amount to get a second saber that has all those features, PLUS you will still have that first saber as a stunt saber, maybe it’s worth $Small-amount extra. For me, that was the case. For you, right now, it might not be, but do take a look at it.