First of all you need to check the path of your feeds in feeds.conf.default and then:

./scripts/feeds update zninux
./scripts/feeds install olsrd-ninux
./scripts/feeds install -p packages -a

This will change your .config, so make sure to checkout again the .config file with

git checkout .config

if you want exactly the configuration of the Sburratone firmware

you are now ready for "make"

How to compile this SDK
-----------------------

Please make sure that you have installed all packages that are required
for OpenWRT (refer to dev.openwrt.org for more information).
Some of the packages that probably are required (list can be incomplete):

bash
make
gcc
quilt
bison
flex
autoconf
libtool
libncurses5-dev
subversion
wget
g++
gawk
zlib1g-dev
cvs
yui-compressor

Step by step instructions
-------------------------

1. Extract files

$ tar xjvf SDK.UBNT.v5.3.3.tar.bz2

2. Build

$ cd SDK.UBNT.v5.3.3/openwrt
$ make

3. Look for firmware file (with prefix XM) in openwrt/bin/.

Good luck!