A few tips.
Before starting, turn off the PSU, > unplug from the wall socket > press the case power on button and hold for about 5 second.
Remove all external hardware/cabling, > detach all internal wiring, except to the CPU cooler fan.
Remove the video card, do not remove CPU assemble or RAM.
When you have stripped the case.
Very gentle remove the I/O shield, it pushes into the case, it needs to be fitted into your new case.
Check carefully the standoffs in the new case, (if installed), they must match exactly the pattern and number of screw holes in the MB, no extra ones under the board, or a short will happen.