Step 1. First, go ahead and download the ROM zip file and copy the whole file over to your phone’s internal storage or microSD card. DO NOT UNZIP the ROM zip file. Mac OSX usually automatically unzips the zip file but just use the zip file not the folder.
Sometimes there may be several zip files, usually the ROM and Gapps or other mods. Copy all of them over to your phone’s internal storage or microSD card. For multiple files, you simply have to install the ROM first then the rest.
Step 2. First, reboot into ClockworkMod Recovery by holding down Volume Up, Center Home, and Power buttons together for 10 seconds.