first thing would be to find out wether or not you have the etm. thats the electronic throttle, if you have this then fitting the mbc is a waste of time as the car wont allow you to go above standard boost unless the car is remapped.
if you have a throttle cable then you need to fit the boost gauge. i used
THIS GUIDE it's not brilliant but a few searches will help.
with the mbc have a look at the diagram below.
you can see the turbo and the boost control solenoid(bcs). all you do is, on the bcs side, disconnect the blue pipe and block it off. with the yellow and green pipes, take them off the bcs and connect them together with your mbc. voila!!
if adjusting the mbc has no effect on boost you may have the mbc connected the wrong way.