need help with hooking up autometer gauges

That's right. You can remove the wires from the original cluster plug and splice. It would be better though to add connector's so you can easily disconnect the wires later. And be sure to connect the ground wires for the new gauges to a good ground - dash frame, pedal assembly, etc.

If you have a volt/ohm meter or test light it wouldn't be a bad idea to check each of those wires. The DkBlue w/tracer should have 12v when the key is in the run position, and the orange should have 12v when you turn the headlights on.