for(let aField = 1; aField <= ActiveDocument.Fields.Count; aField++) {
    ActiveDocument.Fields.Item(aField).Delete()
}
let myRange = ActiveDocument.Sections.Item(1).Footers.Item(wdHeaderFooterPrimary).Range
for(let a = 1; a <= myRange.Fields.Count; a++) {
    myRange.Fields.Item(a).Delete()
}