Add-On Method:

1:Copy the superman folder to
Grand Theft Auto V/mods/update/x64/dlcpacks

2:And open
Grand Theft Auto V/mods/update/update.rpf/common/data/dlclist.xml
Add new line 

<Item>dlcpacks:/superman/</Item>

And save, You're all set!


Replace Method:

Replace files p_tumbler_cs2_s_trev and p_tumbler_01_s in
Grand Theft Auto V/x64g/levels/gta5/generic/cutsobjects.rpf 
with the ones given in the "Replace" folder (make sure to copy x64g to mods folder, and to backup the files that are being replaced)