Mod Collection:This mod collection includes all of Sonic Generations mods included in this list in one neat place so it's easier to download and it's including guides and installations. If you have issues with the HMM you can try SonicGMI.

Run the HedgeModManager.exe (Windows may warn you that it doesn't know the executeable but you can safely click on More Information and then Run Anyway).Download the latest release of the HMM (HedgeModManager), by clicking on HedgeModManager.zip (in Assests).