Changing size of thumbnails?

I would like to change the size of thumbnails!! How can I do this?

Right now, you need to customize your skin.

In Version 1, all the customization were lost when you update the plugin, in Version 2 you can copy the skin folder to your theme and customize it, so the customization wont be list when you update our plugin.

Make a folder i.e. nimble-portfolio in your theme folder, and copy skins folder from our plugin to nimble-portfolio of your theme folder. Modify items.php (line# 19) and change 480×480 size to your liking.

Version 2 has many improvements, actually a completely new and modern plugin.

I hope you like, if you got any problem please let us know, we will try our best to satisfy you.

Hi.
I’ve tried the very same thing as above, but the external skins folder doesn’t work at all.
One thing I’d like to ask is how to “modify items.php”. What kind of lines should I write in items.php in order to connect external files to the nimble core?