weapon mods

How do i remove the icy part and replace it with something like sundering

If you want to change the weapon mod, just get a sundering mod, double-click the sundering mod, and click on your weapon. You'll get a warning asking you if you really want to do it; choose yes.

I think he wanted to keep the Icy hilt. That isn't possible, annoyingly.

I dont think he would have asked "How do i remove the icy part" The Pointless unless he meant to...remove it.

Not my fault people word their questions badly, but still, something for those with the sense to use the Search feature:

You can't remove an upgrade unless you salvage the weapon, which destroys the weapon itself and also includes the risk of getting the other mod instead.
When adding a new upgrade you'll have to just add it like you would to a clean, unmodified weapon, which would destroy the old upgrade.

Should cover everything you need to know, ilikechowfun.