Go to those URLs directly in your browser and download them. I have written them down here to make it easier:
https://runtime.fivem.net/patches/GTA_V_Patch_1_0_1103_2.exe
https://patches.rockstargames.com/prod/socialclub/Social-Club-v1.2.1.9-Setup.exe
https://runtime.fivem.net/patches/GTA_V_Launcher_1_0_1103_2.exe
Once you have them 3 exe files downloaded go put them in:
FiveM Application Data/cache/game