There's so many ways to skin this cat...
Maybe you could review the steps in this guide
http://wiki.tinycorelinux.net/wiki:install_usb_stepbystep "Option 1"
Then simply substitute the tinycore/coreplus ISO with corepure64 ISO where necessary to ensure x86_64 compatibility??
Have you mentioned what type of media you're attempting to install too? USB thumb drive? HDD? dedicated drive or separate partition?
Basically you need only 4 steps,
- install a boot manager,
- copy corpure64 and vmlinuz64 to a /boot directory,
- copy the contents of (ISO)/cde to (drive)/tce
- confirm the paths and names for "corpure64" and "vmlinuz64" are correct within the boot config file and you should be good to go.
As previously mention you could use tc-install making sure you use corepure64 current ISO