How do you set cam timing on a pulsar N13

[macca_slasher]

I have an 87 PulsarQ 1.8 Fuel injected. The previous owner fitted a new head to the vehicle and i think they have put the timing belt back on the camshaft sprocket in the wrong place. The car sounds bad, has no go at all, is pressurising really bad and blowing oil outta the filler cap. My question is how do i set up the camshaft timing. This is my idea on how to do it if its wrong can someone please correct me. Get number one piston to top dead center on compression stroke. line up the harmonic balancer notch with the needle on the motor. Take the timing belt off the camshaft and rotate the cam until both exhaust and inlet valves on number 1 are closed and the cam is just rocking on them.
thnx in advance for any help.