Just did this last month. This is for MK4, but it is pretty good.
https://www.youtube.com/watch?v=4a1BJ-b30T4
Here are some differences. You will have to remove the inner skirting (really straight forward just torx screws) to get access to the top two bolts to remove shock. This likely does not apply to GTD, but on my GTI on side with gas tank there is mechanism to not allow evaporation back into environment, it is in the way of one of the bolts. It is removed with one bolt and then it lifts up and out and can then hang there while you remove bolt for shock. You can not see the hook it slides into from the front. It is a very straightforward job. The fronts are significantly more challenging.
It can be a challenge removing the bolt holding the shock onto the shock mount. It is an allen to hold strut from turning, but then grabbing onto the socket to loosen nut is a challenge. It is recessed so a open end will not fit. I found a socket with a hole in side and then was able to get another implement in to turn socket while allen went through hole in top of socket to hold strut. When you have it out, look at your tools and scratch your head and you should be able to figure it out. They do make special tools for doing.
Folks like the Bilstein. It is my understanding that the B6 has the same extended length as the OE shock while a B8 is shorter for use with lowering springs. I have Koni yellow sports which are adjustable, I like them.
I was reasonably happy with the stock shocks, but I lowered my vehicle and started to noticed dampening degradation (got bouncy) in the rears after a couple years of use on lowered springs. If you did not go with a performance shock such as Koni or Bilstein, If it was me, I would go OEM rather then Munro as I know the OEM damper is a quality product.