Assuming you are using EQ2MAP, use your text editor to open the file
EverQuest II\UI\<
your custom UI folder>\eq2map2\_Skinnable_WindowElementsMini.xml
and add
Visible="false" on Line 3 as shown below. You will also want to add
_Skinnable_WindowElementsMini.xml to the ignore list so it won't get overwritten when you check for EQ2MAP updates.