G5 CD Tray not sliding out

I bought a new hard drive to install to my G5, that went well, but the problem came when i'm trying to boot up the computer and inserting the installation CD, I tried to go over the steps like holding down the mouse then press start wait till tray slides out, or press and hold the c key. and nothing works! wondering what is the problem do i need another trip down the apple store or is it something i can solve?