Just use the same installer and on the first screen you see choose the 64 bit installer.
It has a different location on the hard drive so that should do it.
Cubase 7.5.x, vienna ensemble pro 5,
Master:laptop Clevo, W170, i7 2760Qm, 16 gig, 2xSSD samsung 840pro/evo, +touch screen
Slave: desktop: Titanus, Q8440, 8 gig, 2x WD HDD + SSD
Sound: Motu Ultralite MKIII (usb)
control: Synergy, novation zero SL
vsti: Steinberg, East West, Vienna, Native Instruments, and a lot of others