How to install hot and cold water to sink valve

[Newbie625846]

Hi folks,
Newbie here.

I'm having trouble connecting the washing machine hot and cold water valve to the below sink. As you can see in the picture, the valve is already connected to the sink above it. I would like to confirm whether I need to unbolt the below hex cap so that I can connect the hot and cold water hose from the washing machine. If so, what tool can I use to unscrew it? I can't find the right tool.
Please help and advise. Thanks

 

[cjg]

shut both valves off, and get a spanner<!!!!

 

[RayW]

shut both valves off, and get a spanner<!!!!

and then fit these ...

2 Pieces 1/2" Copper Brass Tee Fitting Tube Connector T-Junction Male Female | eBay UK

This fitting is suitable for brass, aluminum, and steel tubing，widely used in tap, water, fuel, gase pipeline. 2 Pieces Tee Fittings. Color: Copper. Forged brass, thickened wall, high quality and durable.

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[cjg]

and then fit these ***

why fit them when the base is already for washer to go on.