Changing unit damage

Is it possible to alter unit's damage output using only triggers and nothing else?
Say, i have a footie which does 10-12 damage and i want to make him into the same footie, but with 110-120 damage. At the same time, i don't want to use upgrades and don't want to have any green plus numbers on that unit stats window.

That is not possible.

Get World Editor Unlimited

Is it possible in WEU?
If it is, what trigger strings exactly does it write to accomplish this?

Question, how come you don't want to use upgrades? you can hide the (1) or w/e appears when you upgrade and it would work fine.

Maybe he wants to be able to switch it back (you can't unlearn upgrades, from what I am aware)

maybe you could have an upgrade that weakens the attack of the units