how do I connect the cnc machine to my computer to drive it? D(3)600 Stepcraft

Hello to all users!

I am new to cnc machine, and made myself effort

by buying the Stepcraft D(3)600 (UCCNC kit bundle), instead of a Chinese machine, (twice the price anyway)
Today, after much application, I finished mounting it, and connecting the motherboard, up to step 9 of the p74 assembly manual.
Step at which, it is necessary to connect to the PC before tightening the screws,
and that's where the error is, because there is no plug to connect the UC100 parallel/USB socket on the machine,

So my question is, how do I connect the cnc machine to my computer to drive it?

I called today the repair service which explains to me that it is necessary to disconnect the black plug of the motherboard (on the photo) to connect the UC100 socket (from what I understood in my English approximate), but:
1- it's impossible to disassemble
2- the pins would not be opposite the holes

However, I studied everything well before buying it so as not to be mistaken, and not to forget anything when ordering.

It is also well specified on the Stepcraft shop 'Complete CNC DIY kit including all mechanical and electronic components'

But I really don't see how to connect it without buying the Parallel Module OEM Package (parallel interface) 10100 at 20€ + 20€ shipping costs (thanks Stepcraft)
this should have been specified somewhere (there is 1 line on the UCCNC notice)

Today, I am therefore informing you of my disappointment on this 1st day, and will have to go to the checkout, when it should not be the case since: kit including all mechanical and electronic components ',

I hope it will help you to think about ordering this thing, and that Stepcraft will include this module directly in the box because I don't find it very professional.

I hope the future will be brighter in its use

Thank you for your support

Olivier (a french grouch B) )