1.Copy xml file to the GTA V > Menyoo Stuff > Spooner
2.Ingame press F8 > Object spooner > Manage Saved files > M Helipad V1 > Load Placements
3.Wait few seconds..!
Enjoy..!

YMAP
1.Paste ymap file into Grand Theft Auto V\mods\update\x64\dlcpacks\custom_maps\dlc.rpf\x64\levels\gta5\_citye\maps\custom_maps.rpf\

2.If you dont have cutom_maps installed then copy custom_maps folder to mods\update\x64\dlcpacks
3.Goto mods\update\update.rpf\common\data then right click on dlclist.xml and click edit then add this line at the bottom <Item>dlcpacks:\custom_maps\</Item>
4.That's it enjoy..!