Before drilling a hole in the drawer, you need to know exactly where to drill not only here but also in the cabinet, which is where we'll be mounting the Blumotion springs and dampers. The easiest way to do this is to remove a rail from the cabinet, fit it to the drawer and mark your mounting points on the drawer (use masking tape) and measure your offsets from the cabinet front and bottom edge of the rail.
Note that if your existing drawer system closes itself under gravity for the last 5cm (2") of travel, then your Blumotion system will need to be installed at the same angle. In my case, this angle was 2.5mm (0.1") down for the last 5cm (2") of travel, or a gradient of 1/20. The pictures in the next step will make this clear.
Once you know where to drill, installing the bolt is quite simple. I recommend using a split ring washer or a lock nut to ensure the bolt does not come loose over time.
As for the length of the bolt, the aim is to miss the cabinet wall by about 2mm (0.08"). Choose a longer bolt and cut/file away as necessary.
I prefer to keep the bolts as hidden as possible, so I've installed mine on the far side of the kitchen. Note that the second and third pictures in this step are of drawers on opposite sides of my kitchen.