This is the thread where you can download JBM:
[Mods] Jakebitesmods V18 For D2 Ota Gb Kernel All Roms! [Mods] - RootzWiki
flash it in recovery. The phone will appear to bootloop once, that's normal due to the governor he is using. When it reboots completely, you should be able to access modcentral.
PS - the point of JBMGUI is that you don't HAVE to use modcentral. It's supposed to supply you with a graphical way to enable/disable the mods.