Command line to check the version

We can use this command to check whether the linux is 32 bits or 64 bits:

uname -m

if the output is i686, then it is 32 bits;

if the output is x86_64, then it is 64 bits.

How to change the icon of an application

First of all, copy the new icon into clipboard;

Then, open the Info window for the application (File » Get Info, or Command-I), click the icon in that window (a blue border will appear), and paste in a new icon.