1. Quest Reward: Players can receive Skill Retrainers as rewards for completing certain quests in the game. These quests can be obtained from NPCs or randomly generated during gameplay.
2. Drop from Enemies: Some specific enemy types in Hellgate: London have a chance to drop Skill Retrainers upon being defeated. Players may find these enemies throughout the game, but the drop rates can be relatively low.
It's important to note that Skill Retrainers are quite valuable and can be sold to Merchants for a hefty amount of Credits (in-game currency). Hence, players may consider using them judiciously to optimize their character builds or save them to purchase powerful items or equipment.