Hitch and wire harness installation

I bought a package deal on Ebay for a Hitch and it came with everything. However the wire installation looks difficult from what I saw on youtube. It came with the 87438 - Pro Series 51 Receiver Class III, Black Powder Coat hitch and 118520 - T-One Connector Assembly w/ Converter wire harness. I've been reading that the stock wire harness from Mazda Usa website is easier to install it is part 0000-8E-N13B. Would this work with the type of Hitch I purchased in the package. Can anyone help?

The wiring is independent of the hitch. I used the OEM harness and it worked out very well. I would recommend it for sure

Okay thank you so much. Will do.

Just remembered. Make sure you have the factory plug in the rear for the harness. I believe it comes standard on the GT models.