To start off, let's tinker the socks.
Open up your file in Tinker.
A little window should pop up that says Select Sprite to Edit.
Since we want to edit the file in the closet, select CLOT_SOCKSWHITE_AWAY and hit Edit (you may need to scroll to see the edit button).
Next, on the top menu, click Toy -> Palette -> Babyz. This will switch your files over to the babyz color palette.
Now, Click on the little [+] next to Away in the left menu and select the line that starts with Frame.
Some clothing types will have multiple frames that will need to be edited, but this file has only one.
Once you click on this file, you should see the picture of your item in the main window.
Now, you have two options. You can edit Tinker bases from templates (which Babyz.org has under the tutorials section) or you can export a copy to edit directly from Tinker.
Either way, open up the Tinker base in an image editing program and modify it as you'd like. Save it as a PNG type.
Here's my tinker image for the socks:
Back in Tinker, click the Import button. Locate the modified Tinker file and hit open. You should now see your modified tinker file in the main window. You would repeat this process if there were multiple frames.
Hit save and check the file in game. If everything went okay, your file should show up with your modified tinker image.
And that is pretty much all there is to Tinkering! You can also modify the other sprites (the non-away ones) if you'd like to, but I'm usually too lazy.
On to: General Stuff - Part 2