Im kind of disappointed i have bought one license and thinking of buying one moore for a second forum but for me to be full ended i nead to learn how to make my own node icons becouse i dont understand this new node-stripe.png how it works and i dont know how to configure my own background on xenforo it doesnt matter what i do the size is wrong and im making threads all over the place and dont get one answer people only ignores im still learning but how will i learn if nobody answer my threads? people only have "google it" in there minds.
What a waste of time..
Don't be disappointed - not everyone is able to grasp all of the new bits and bobs in XF and a lot of site owners don't necessarily have design skills or know how to modify sprite sheets (or even understand what they are).
Half the issue your experiencing is your needing to learn basic css. Clickfinity posted some good info I encourage you to read and he's offered further support when and if you require it. The other half of the issue your having is not xenforo related as this is a design issue your having, and the fact your wanting to design custom graphics. I've linked to a free editor and I've only just read your reply that you use photoshop so I'd suggest googling "photoshop tutorials" or better still this site shows you and teaches you how to use the tools in photoshop so your able to fluent yourself in designing graphics using the tools of PS. http://www.heathrowe.com/
I'll try and compile a spritesheet guide when time permits but Clickfinity explains it nicely and there's spritesheet generators throughout the web that allow you to drag and drop images onto which makes it even easier and less painless.
Is that what you are looking to do? If so, I can explain it more carefully.....
EDIT - the thread referenced above does that perfectly! Just a replace the existing with the new situation!
I do notice that a lot of answers here are very accurate...but sometimes forget to walk a person through every single step. That is, they often assume some prior knowledge of the flow of XF. Even the installation of add-ons is a little murky until you try to understand how exactly they are formatted...
I suppose as the years go by, community members will add various guides for Dummies (like me).