You can donate using
1. PayPal : donate (USD)
2. WebMoney system:
WME: E402143441138WMR: R135486086479
3. Yandex money: 410011819820953
HoMM3 HD patch remains a free application regardless of your decision to donate. You are neither required nor obligated, legally or morally, to donate in order to use the patch, and contribution is strictly voluntary.