As title, my car has developed some new funny noises over the last few weeks and it seemed down on power but i just thought i was being paranoid and thet i had got used to the power............................................. .................................................. .................... I WAS WRONG

Took my friend out for a spin and he said it deffo wasn't a quick as it used to be and the exhaust seemed blowy, turns out i've somehow lost 3 of my exhaust studs at some point!

What i want to know is :
A) How the hell did they fall out without me hearing a big clanging noise
B) How hard is it to take the turbo & manifold off (4X4)
C) What size studs are used originaly

Any help would be greatly appreciated

Thanks,

Dave