Switching from Ranged to Melee

Ok, I'm basically attempting to have a unit switch from a ranged attack to a melee attack when it comes within range of an enemy unit. I already posted on this in the Gen Development section hoping I was missing something in the unit data. Panto made the suggestion that i should probably use an orb ability combined with a trigger to get it to work. I've been working at it for a bit now and I've come to the conclusion that I'm completly lost :< . I'm gonna keep working at it but was hoping if any one has any brainstorms or knows how to do it they could help me out. Thanks.

P.S. I want to make the units weapons change, (from spear to sword) but I'm guessing that has to do with editing the model or removing the unit from the map and having a trigger replace it with a new one?

u use minimum range

Yeah I tried that but that applies to both attacks. I need it to switch off between attack 1 and attack 2. Thanks though.