Change HP of unit

How can i change the max HP of a unit?
i.e a unit has max hp 500, how can i change that so it has max hp 600?

Object editor in the WE. It's under Stats - Max HP (Base).

Unless you mean with a trigger, in which case it'd probably have to just switch the unit with a slightly better version.

ohh, i meant, in game.
Thx for the help!

Yeah, then you just need a second unit that is exactly the same, but with more HP.

To change hit points in game it really depends.

If you want every unit owned by a player to change its hp by a percentage, you can use Handicaps

If you just want to change a unit's HP by 100 you can just add to it a custom ability that adds 100 hit points to the unit.

If you want to change a unit's HP by a X quantity of points you'll need to use weaaddar's bonus mod

This is great! I saw that he hade some more nice stuff but this is realy what i need. But, how to "install" it? Were do i put the code?