I have to replace the headgasket on a Chevrolet Optra, wich is the same as a Daewoo Lacetti. We got a 2.0L version of the D-TEC engine. I searched a lot but didn't find everything I need to start the job.
I find on this forum an how-to for the 1.6L engine. I think it's the same way to do but the camgears alignement is different, right?
http://www.daewootech.com/forum/viewtopic.php?t=2746
http://daewootech.com/forum/viewtopic.php?f=19&t=10306
Do I absolutely need to replace the water pump? I read over the internet that the pump will leak after moving it to release/tighten the timing belt.
Do I also need the special tool to move the water pump?
Now for the head torque.. I found the torque sequence for the GM familly 1 engines (we have Chevrolet Aveo with 1.6L E-TEC also, the engine look the same but I have no idea if it's the same)

And the torque is 25Nm (18lbs ft) + 60° + 60° + 60° + 10°. Is it the same as the 2.0L?
Thank you for your help, I appreciate!