Clearing XML menu to load another

I have a menu that is populated by XML, I’d like to know how I can clear that menu to load another one in it’s place.

I can get the other menu to load but it’s adding itself to the previously generated menu:

so let’s say I have an XML document that has <menuItem> nodes that have nodes within them named [this is the default menu]:

bread
basket
wheat
hay

and another XML with the following:

orange
peach
lemon
apple

What I’d like is when i hit a button let’s say “Fruit”
It Loads:

orange
peach
lemon
apple

and only those.

right now it loads:

bread
basket
wheat
hay
…and attaches:
orange
peach
lemon
apple

how can i clear the XML or for loop that created the buttons so that the newly loaded menu from the newly loaded xml is the only menu that is displayed and not tacked on to the existing menu?

Thanks in advance guys!