[Koha] error when install koha 3.0 in ubuntu

hi, i already download koha 3.0 when i try to install by refer to http://www.blazingmoon.org/guides/k3-on-u810-5.html, the error was out like this : /build/koha-3.00.00/INSTALL bash: /build/koha-3.00.00/INSTALL: Permission denied