asking for procedure and accessories to connect 2- 4k monitors to my mini M1

From the M1 Mini's standpoint, you need to connect one of the monitors via USB-C / Thunderbolt, and the other via HDMI.

Mac mini (M1, 2020) - Technical specifications

Some monitors take USB-C (DisplayPort) input. If your monitor doesn't take that type of input, or you don't want to use it, there are many 6-foot adapter cables that go from USB-C to DisplayPort, Mini DisplayPort, or HDMI. It's just a matter of picking one with the right connectors that is advertised as supporting 4K resolution.

What brand and model are the 4k monitors?

For connecting displays to the M1 Mac mini, see > Connect a display to Mac mini - Apple Support