Default [Q] How to Install a Custom Rom on Galaxy Gio?

Hi! I am newbie to flashing roms. This the first time I am gonna flash a custom rom. I installed a custom kernel before but due to lack of my skills and experience, I got stuck in boot loop. Then I got it repaired. Now once again, I wanted to flash a rom but with step by step guide from you people. I have rooted and installed cmw recovery on my Gio successfully. I have downloaded adrenaline rom second edition zip file and put it in my sdcard. There is something like mount system or data. I am currently on stock rom. Here is the link to adrenaline rom 2nd edition:

Please help me. I do not want to brick my phone or stuck in bootloop. Thanks in advance!