How to remove Thinkpad 600 keyboard

Hi, I have an old thinkpad 600 which I want to dismantle to reset the bios password chip. I have checked the manual, and removed all screws underneath and the one on top of the lower casing, but I am not able to angle the front of the keyboard and its frame enough to reach the ribbon cable to disconnect them. Please will someone take pity on my and tell me what I am doing wrong. The manual shows the keyboard just lifting up at the front to gain access to the cables at the rear. But I am afraid of breaking the plastic frame or worse still damaging the ribbon cables. Is there a trick to this?