is it possible to edit items of a listbox in excel VBA

Use additem or removeitem only if it concerns only 1 item.

Otherwise you best use .list
You can populate a listbox/combobox in 1 go using List & array:

Listbox1.list=Array("yes","no","never","Don't know","Neither of those")

Combobox1.List=split("one|two|three|four|five|six|seven","|")

combobox1.list=[row(1:20)]

Listbox1.List=range("A1:D20").Value

You can change a value in a listbo/combobox also using .list

Combobox1.list=split("one|two|three|four|five|six|seven","|")
Combobox1.List(4)="fifteen"

if the combobox/listbox contains a multidimensional array

Listbox1.List=range("A1:D20").Value
Listbox1.list(4,3)="remarkable"