I assume that you are using the default UI? The best thing to do is make a new folder in your uifiles folder for a custom UI. You can then download a custom spell bar at
eqinterface.com. To find the spell bars, click on the Downloads link on the left, interface pieces, and then spell bar. Then find the spell bar you like, download it and then unzip it if it's zipped up and stick the xml file in that custom ui folder you made. In game, ALT O to open the options window, on the general tab click on the Load UI Skin button and choose the custom ui folder you made. That will load the spell bar you downloaded.
Now hopefully the spell bar you downloaded is up to date and it loads. You'll come across some that haven't been updated in years.
You can also download a completely custom ui from that same site as well, I would stick to either the featured ui's or complete sets, they are usually updated. There are many great UI authors that still keep their UI's up to date. My ui is a mix of different authors pieces and some completely built by myself. If you want to customize your window pieces, let me me know I can can show you what to do.
Edited, Sep 22nd 2018 11:01am by Gidono