Sure
hook your phone up to your PC, you should have a prompt or window open automatically, a window of your GN files (virtual sd card), drag and drop the dnld'd bootanimation zip file onto your virtual sd card (NOT inside another folder). Reboot into recovery either through rom manager or if the rom you run its advanced power menu and flash. Install zip from sdcard, choose zip, find it, confirm it. I assumed you are on Windows7 ?