Granted I'm not experienced in electronics, but being able to connect the wires to an upgraded 30A power supply and measuring VREFs with a multimeter after watching or reading a tutorial, I don't think this should be hard for me to grasp.
However, I just can't find a tutorial explaining this anywhere.

Basically the first 3d printer I got and am using right now (Solidoodle 4) uses an undersized (15x15 for 20x20 bed) silicone heat pad and provides uneven heat distribution. BTW, I don't care about heating speed.
This causes warping/lifting/unsticking with almost every object I try to print with all the adhesion techniques (kapton tape, glass with hairspray/glue stick, etc).

So I ordered a geeetech 214x214 PCB heatbed with the LED and thermistor presoldered.
But I can't find a tutorial on how I should connect it, only tutorials on soldering the power wires.

I'm wondering if I can just connect the power wires to the connector on the motherboard the current silicone heat pad is connected to.
Some people say that's fine, others say they tried doing the same with larger silicone pads and burned their motherboard, and suggest to use a relay while I can't find any info on what/how that's used for in a 3d printer.

So am I good connecting to the existing connector used by the silicone heat pad? Again, I don't know electronics.