if you have the soldering skills led are replaceable..
if your saying 5 out then i think its more to do with which component controls these leds,
as led have a long life span you can have 1 fail but having 5 failed i don't think its the led..
picture would be good..
Quite often it is the boot closing action that kills the LED's or the solder joints of the LED's. Big problem on the TT centre brake light.
Would be easily repairable (with some LED's and a soldering iron) but as mentioned, annoyingly, they are usually sealed units.
Incidentally, I am aware that some owners have had a positive result in getting TT centre brake lights replaced under goodwill outside of warranty, so may be worth having a conversation with a dealer or two. If it is a sealed unit, it is not like they can realistically class it the same as a serviceable bulb....although many will try !