One question...

Theme: Pad, soldering point, via, plated-through hole

How do I change all the drill holes of the circuit at once?
If you really want to change all drill holes of the components of the PCB, please type [Ctrl] + [a] to select everything. Then type [e] for edit and select only the solder points in the big edit dialog:

1 (Fig. 1: The big edit dialog)

In the following solder pad dialog you change the drill
hole diameter:

2 (Fig. 2: Change drill hole)

If you only want to change the drill diameters of 0.8 mm to 0.85 mm, it is best to use the selection assistant in the "Edit" menu:

3 (Fig. 3: Selection assistant)

Click on [Start], then on [ OK ], then on [Close]. After that, directly type [e] for Edit, as described above.