To spaceship parts To the written notes To the real estate sale signs Epsilon Track Parachuting (unknown height) Jump tricks (unknown height) Peyotes (unknown height) Hidden packages (unknown height) F4 to open NUMPAD 5 to select NUMPAD 8 top NUMPAD 2 down P.s Unknown height is inaccurate coordinates, you may be near but not right at this place.
You will need ScripHookV. You can download it on LibertyCity.ru in the Miscellaneous files section. Download and unzip the archive, move CollectableCollector.asi to the game directory where the ScriptHook is located.