Selling off inventory

Just wondering for all the shop owners/managers, how to get rid of old bike inventory thats not selling? I have a several carbon full sus mtbs i cant get rid of and dont wanna get in trouble with my brands as they dont allow 3rd party sales (ebay, PB, CL, FB). But i gotta sell em and move on. Ive started a separate FB account not linked to my personal one to use marketplace, but still not selling anything. Yall got any advice?