Download Magic.Txd https://www.mixmods.com.br/2016/04/programa-magictxd-criar-e-editar-txd.html
After installing Magic.txd on your PC open the file ''magic.txd.exe'', and then open the file ''hud.txd'' which is in the folder of GTA IV hud, then you replace the '' hud_sniper'' with what you downloaded, and then just save and have fun with the new Sniper crosshair.