[teddyboy420]

You use multiple add-ons in much the same way you use one. You simply put all the add-ons in the same folder...

So lets take the two mods you mentioned as an example. You'd create a folder in the UI folder of your EQ2 directory, C:\...\EverQuest2\UI named whatever you like, but for this example we'll pretend you name it "Custom". So the path would look like:

C:\....\Everquest2\UI\Custom

You'd unzip the filed from Drums group window and drop em into your "Custom" folder. Then, you unzip the raid mod, and drop it in the same folder you put the group files into. So all of the files from the two separate zips are now in

C:\....\Everquest2\UI\Custom

Create your EQ2.ini (there are instructions for doing so on the FAQ of this site), or use one of the ones Drums includes (if he does so), and load up the game and that should do it.

As a side note, if there are any extra steps needed to get a mod working with other mods, the author will usually include instructions in the add-ons description.