Extract, emulate bcm7552-img.tgz?

so i sniffed my set-up box and i found this bcm7552-img.tgz test image for my set-up box wich contains kernel.gz, rootfs.ubi and logo.bin and i was wonderin if anyone can extract rootfs.ubi or emulate image on linux since im a noob with linux im a windows user?? thanks for your time

yeah i can open using winrar on windows but im asking to extract rootfs.ubi or emulate the whole image. whats inside the image