Is there anyway to install Ubuntu (server) on Airlive WL-5460AP access point device?
With 2MB Flash, 16MB SDRAM and an unknown processor architecture, I'm going to have to say no. The server kernel alone would fill this several times over.
This really isn't the level of device that Ubuntu is aimed at. For this you want something like DD-WRT, although on their forums the requirements are still too restrictive even for that. I don't think you're going to have much luck in customising this.