What will I need (tools, parts) to replace timming chain guide.

My car started running half idle and stalling so on. Found out about these plastic timming chain guides had to be replaced. I checked it. It's broke. The car still runs even though i'm no longer driving it cause I hear horror stories about if it jumps time. I wonder have I done damage to it already? Because when I pull the coil wires from the passenger side of the motor(same side as the broken guide)it does not change idle of engine. I know the motor only has 26000 miles on it. I need to know what I need to get(besides a book) to fix it? Do I have to chang tentioner/s also, both sides? Timming chain/s. I know I need a tool to hold it still? Thank you