From IconPackager to Objectdock

Extract the icons and then save them in a folder inside C:\Programs\Stardock\ObjectDock...that's what I do.

oh, and then rightclick on the icon in your dock you want to change and select Dock Entry Properties then Change Image and the navigate to the image you want. (The image doesn't have to be inside the above folder, it just makes it easier for me is all)

Normally if an icon is change by IP, then when you drag it to the dock it uses that icon

else, you can download a package then extract the contents to another folder

Another good way for say a program using an .exe file. Is to use Icon Developer to open the .exe file and it will give you an icon. Which while open in Icon Developer you can right click the icon there in ID and export it to the Object Dock Library / images for easier use and finding at a later date again.
I do this and also have a icon image library there for lots of things I change around.
That location again is documents/objectdock library/images.
Then when you go to change a Object Dock image it comes up in the library in the images section. This also changes the icon to a png image file. Which I always use for OD.
Hope this helps you a bit.

SGT

Only double click and this installing itself

Not for most of the dock icons it doesn't. They have to be changed manually.

i think only png is for objectdock

No you can use just about anything, jpg gif png, it doesn't really care. When you browse for an image it will list the supported file formats.

Nope icons, .ico, work as well, but generally speaking png images will be higher quality.