Tomb Raider I-III Remastered Starring Lara Croft

During the playthrough of "The Golden Mask" expansion, during the second level "Fool's Gold"; The level has windows with the soviet symbol sketched on them. Do not break them. 3/4 of the way through the level, there is a high rise window with a shotgun goon within, accessible via a ladder, (where you pick up two sets of grenades and the grenade launcher). In order to enter the room, a window is required to be damaged. DO NOT BREAK THIS YOURSELF. Allow the goon to break one of the windows himself and then enter. This does not void the achievement, and results in being able to chase the 100% collectables during gameplay. Unlocks on result screen at end of the level.