Ok I'm no 1.8T expert but I've rebuilt many engines before and in order to get the piston out of the engine you must remove the pistion and connecting rod togerther by removing the connecting rod end cap from around the crankshaft. Then pulling the assembly out through the top of the engine. Ok now, Pressed In, my refer to the wrist pin being pressed into the pistion to hold the connecting rod-pistion assembly together or the wrist pin could be held in by "C" clips all engines are different. Or Pressed In, could mean the new connecting rod bearing which "wrap around" the cranksaft need to be pressed into the connecting rod and end cap, I guessing this it what it means and thats why is states "Torque angle method" which I've never heard before. Call your local rebuild shop and ask them some questions about it.
The Torque Angle Method is simply a technique to properly pre-load a 'stretch bolt'.
Basically it means you calculate how much stretch you will get from X turns based on the pitch of the bolt thread. It is often used in blind installations when you can't use a more accurate measurement.
There are many reasons why this is not the most accurate way (even though it's probably the most common), including but not limited to; plastic deformation of the threads that cannot be accurately accounted for, differences in thermal expansion ratios for different materials, etc. These concerns however are really only relevent for generic applications. In the case of your rebuild, they should specify the torque angle, and it will be specific for that bolt, and the parts it's holding (such that they know the torque angle from the design and prototyping and have measured more accurately the actual bolt stretch with a guage when the designed it).
In short there's three was to do it (from most accurate to least):
The Guage Method: Basically a tool to measure stretch when you install it.
The Torque angle method: Described above, and not bad assuming they specify a torque angle based on guage measurements (as I'm assuming they do in your case).
The Torque method: The using a torque measurement to infer the bolt stretch. This is a toughy. Torque measures friction more than stretch. Many time they will say dry or lubricated torque, but what lubricant you use makes a big difference.
Which ever bolt it's refering to, it's just that... a single use stretch bolt, and how to determine the proper stretch.