The built-in guide-delete tool removes all guides from the current context downwards.
So if you are in the model context and run it then all guides go.
If you are inside a group context and run it then all guides inside the group, and inside other groups/components that are inside the context group, will be deleted, but guides outside in other groups or the model itself are not removed.
Note that locking a group or having guides on 'off' layers, does not prevent those guides being deleted in en mass.
Of course you can erase individual guides using the Eraser tool or selecting them and using 'delete'...
There are several script tools to erase guides in different contexts, and also differentiate between guide-lines and guide-points...