Celica Forums General Discussion Interior [HELP] seatbelt replacement

hi all,
could any1 help me pls, i'm getting really confused…
umm my beloved car just failed the nct because of the seatbelt... it was frayed… (still is though..)
been like that for years so i was kinda expecting it…
umm i was looking at the handy repair manual, and it says 'NEVER DISASSEMBLE THE FRONT SEAT OUTER BELT.'
i was also told years ago, that if want the seat belt replaced, i have to get the whole unit replaced (because of the airbag). Does this mean that the frayed belt can't be replaced at all, and have to get the whole unit replaced really?
or am i getting it wrong????
please don't get mad at me if my question is stupid i'm just a blonde girl really and i'm really getting confused and would really appreciate if some1 could school my ass on this topic...
thanks for all your help in advance

It's not because of the air bag, but instead because of safety. If your seatbelt has a weak-point and you're involved in an accident that relies on your seatbelt to protect you from flying forward, the weakest point in your seatbelt is most likely to tear first.

The replacement parts are about $190 USD for each site.
RIGHT Belt & Retractor 73210-2B130-C1
LEFT Belt & Retractor 73220-20830-C1



The installation is simple.