what changes would have to happen to refresher orb (from DoTA) for it to be a balanced item in LoL?

Every single global ult would need to be nerfed (especially ones like Karthus). Anyone based around lots of power while their ults are up and lower power otherwise would need nerfs (Veigar ulting your AP and your AD? Annie using Tibbers WQ twice for a 3 second stun and massive damage? Brand ulting your team? Malphite ult?). A lot of CC's would probably need to be balanced, especially hard CC's (Cho'Gath W'ing twice? Ekko using W while in his W and you can't leave? Morgana Q'ing you for a 6 second snare?).

Honestly don't think it could work without either rebalancing the entire game around it or nerfing it so much it bears little resemblance to refresher orb.

Remove the active and lower the price?

LoL CD's are so low already, refresher wouldn't be that game breaking. Make the item cost more and have less stats, that should keep every champ from buying it. Plus it's another active which proves to be kinda complicated as it is.