We bought a Beachcomber Hot Tub less than a year ago and I know our dealer sells replacement jets and other parts. The jets are removable and the same-sized jets can be moved to another position in the tub. I'm not sure if you can do this while it's full; we don't move our jets around.
Our dealer is very helpful - check to see if there is one near you or call their head office in British Columbia, Canada. Hopefully the dealer closest to you understands that helping you will lead to a satisfied and repeat customer that gives referrals! The dealer - if they value customer service - may even give you a quick run down of the features and functions on the tub; the head office may send you additional info too.
Our foot jets broke - the larger ones in the foot wells and yes, the tub had to be drained for those to be replaced. Just so you know, they're NOT supposed to open, shut or move at all like the ones on the walls. There may also be one more small jet that's 'not working'; it might be the jet that can be used to add an UV filter to the tub.
I'm no expert, but you should check out threads here on decontaminating your tub, especially if there's lots of gunk inside it. We're also going to try the Dichlor then chlorine method on the fill we're doing this weekend as my husband has been having moderate to severe rashes from the hot tub for the last four months which, from threads here, I think may be from over-use of Dichlor.
Keep reading and educating yourself as I've come to realize dealers are not always really knowledgeable on the chemistry of spa water. Again, threads here explain so much about balancing your water and using things like borates and baking soda instead of costly chemicals from a hot tub dealer.
Good luck!